Chicken Broccoli Lasagna with Creamy White Sauce

This chicken broccoli lasagna is a white lasagna: no tomato sauce, just three layers of noodles with shredded chicken, bright broccoli, and mozzarella, all baked in a creamy Parmesan white sauce. The sauce is a simple butter-and-flour base loosened with chicken broth and whole milk, and there’s enough of it (about 6 cups) to keep every layer moist.

It uses cooked chicken, so it’s a good home for a rotisserie bird or leftover roast chicken. Plan on about 25 minutes of prep, 25 minutes at the stove, 45 minutes in a 375°F oven, and a 15-minute rest before you cut it into 8 pieces.

Why You’ll Love This Recipe

• Plenty of sauce: Six cups of white sauce for one 9×13-inch pan means moist, creamy layers instead of dry noodles at the corners.
• Broccoli that stays green: A 90-second blanch and a good pat dry keep the florets crisp-tender, so they don’t water down the sauce.
• Balanced filling: Four cups of chicken is enough to taste in every bite without crowding out the pasta and sauce.
• Clean slices: A 15-minute rest lets the sauce set, so each piece holds its layers.
• Make-ahead friendly: Assemble it up to a day ahead, or freeze it unbaked for a future dinner.

Ingredients

Prep: 25 minutes  |  Cook: 1 hour 10 minutes  |  Rest: 15 minutes  |  Total: 1 hour 50 minutes  |  Yield: 8 servings (one 9×13-inch lasagna)

Equipment: 9×13-inch baking dish (at least 2 1/2 inches deep), large pot, 4-quart saucepan, whisk, slotted spoon or spider, rimmed baking sheet, aluminum foil, instant-read thermometer

• 14 standard lasagna noodles (about 12 ounces; 12 for the layers plus 2 spares)
• 1 tablespoon kosher salt, for the pasta water
• 1 tablespoon olive oil, divided
• 1 pound broccoli florets, cut into 1-inch pieces (about 6 cups)
• 8 tablespoons (1 stick) unsalted butter
• 1 medium yellow onion, finely diced (about 1 1/2 cups)
• 4 garlic cloves, minced
• 1/2 cup all-purpose flour
• 2 cups low-sodium chicken broth
• 3 1/2 cups whole milk
• 1 cup grated Parmesan cheese (about 3 1/2 ounces), divided
• 1 tablespoon Italian seasoning
• 1 teaspoon kosher salt, plus more to taste
• 1/2 teaspoon ground black pepper
• 4 cups shredded cooked chicken (about 1 1/4 pounds)
• 3 cups shredded low-moisture mozzarella cheese (12 ounces), divided
• 2 tablespoons chopped fresh parsley, optional

Ingredient Notes

• Lasagna noodles: Use standard noodles that need boiling. Twelve noodles make three layers of four in a 9×13-inch dish: three laid lengthwise, plus one trimmed to fill the gap at the short end. A 16-ounce box holds more than you need, so cook 14 and keep 2 as spares in case any tear. For oven-ready noodles, see the FAQ.
• Broccoli: Cut the florets to about 1 inch so they lie flat between the noodles. Blanching them briefly and drying them well is the main thing that keeps a white lasagna from turning watery. Raw broccoli goes limp and releases water into the sauce as it bakes.
• Butter, flour, broth, and milk (the white sauce): Eight tablespoons of butter and 1/2 cup of flour thicken 5 1/2 cups of liquid to a pourable sauce about as thick as heavy cream. That may look thin, but the noodles absorb some of it and the cheese adds body in the oven. Broth adds savory flavor, and whole milk keeps the sauce creamy.
• Onion and garlic: A finely diced onion cooked in the butter gives the sauce a sweet, savory base. Four cloves of garlic flavor 6 cups of sauce without taking over.
• Cooked chicken: Shredded rotisserie chicken, leftover roast chicken, or poached breasts all work. Use chicken that’s been refrigerated no more than 3 to 4 days. Four cups is about 1 1/4 pounds of meat, which is roughly what one large rotisserie chicken gives you.
• Parmesan and mozzarella: Half the Parmesan goes into the sauce and half goes on top. Shred a block of low-moisture mozzarella yourself if you can, since it melts more smoothly than bagged shreds. Skip fresh mozzarella here because it releases too much water.
• Salt: The noodle water gets a tablespoon of kosher salt so the pasta is seasoned. The sauce gets just a teaspoon because Parmesan, mozzarella, and rotisserie chicken all add salt. Taste the sauce before layering, and add more only if it tastes flat. If you use Morton kosher salt, which is saltier by volume than Diamond Crystal, use about half as much.

How to Make Chicken Broccoli Lasagna

1. Prep the oven, pan, and pasta water: Heat the oven to 375°F with a rack in the center. Brush a 9×13-inch baking dish (at least 2 1/2 inches deep) with 1 teaspoon of the olive oil. Bring about 5 quarts of water to a boil in a large pot and add the 1 tablespoon of kosher salt for the pasta water.
2. Start the sauce: While the water heats, melt the butter in a 4-quart saucepan over medium heat. Add the onion and cook, stirring often, for 5 to 6 minutes, until soft and translucent but not browned. Stir in the garlic and cook for 30 seconds, until fragrant.
3. Cook the roux and add the liquids: Sprinkle the flour over the onion and cook, stirring constantly, for 2 minutes. Slowly whisk in the chicken broth until smooth, then whisk in the milk a little at a time. Raise the heat to medium-high and bring to a gentle simmer, whisking often and scraping the bottom and corners of the pan. Simmer for 3 to 4 minutes, until the sauce coats the back of a spoon about as thickly as heavy cream.
4. Season the sauce: Remove the pan from the heat. Whisk in 1/2 cup of the Parmesan, the Italian seasoning, the 1 teaspoon of kosher salt, and the black pepper. Taste, and add more salt only if needed. You should have about 6 cups of pourable sauce. Cover the pan to keep it warm.
5. Blanch the broccoli: Add the broccoli to the boiling pasta water and cook for 1 1/2 minutes, just until bright green and still crisp. Lift it out with a slotted spoon or spider into a colander, keeping the water at a boil. Rinse the broccoli briefly under cold water, then spread it on a clean kitchen towel and pat it very dry.
6. Cook the noodles: Add the lasagna noodles to the same boiling water and cook, stirring occasionally, for 2 minutes less than the package's al dente time. Drain them, toss gently with the remaining 2 teaspoons of olive oil, and lay them flat on a baking sheet so they don't stick together. You need 12 whole noodles; the other 2 are spares.
7. Build the first layer: Spread 1 cup of the sauce over the bottom of the baking dish. Lay 3 noodles lengthwise over the sauce, overlapping them slightly, then trim a fourth noodle to fit crosswise across the gap at the short end. Spread 1 1/2 cups of the sauce over the noodles. Scatter half of the chicken and half of the broccoli evenly over the sauce, then sprinkle with 3/4 cup of the mozzarella.
8. Build the second layer: Top with 4 more noodles in the same pattern, 1 1/2 cups of the sauce, the rest of the chicken and broccoli, and another 3/4 cup of the mozzarella.
9. Add the top layer: Lay the last 4 noodles on top and pour the remaining sauce (about 2 cups) over them, spreading it to the edges so every noodle is covered. Sprinkle with the remaining 1 1/2 cups of mozzarella and the remaining 1/2 cup of Parmesan.
10. Bake covered: Tent the dish loosely with foil, arching it so it doesn't touch the cheese, and set the dish on a rimmed baking sheet to catch drips. Bake for 25 minutes.
11. Uncover and brown: Remove the foil and bake for 20 minutes more, until the sauce is bubbling at the edges and in the center, the top is spotted golden, and an instant-read thermometer in the center reads 165°F. For a deeper golden top, broil for 1 to 2 minutes, watching closely.
12. Rest and serve: Let the lasagna rest on a rack for 15 minutes so the sauce sets and the layers hold when cut. Sprinkle with the parsley, if using, cut into 8 pieces, and serve.

Expert Tips

• Dry the broccoli well. Water left on the florets ends up in the sauce. Blot them on a towel while the noodles cook.
• Keep the sauce pourable. It should look like heavy cream when it goes into the dish. A sauce that’s already thick on the stove will bake up pasty, and the top noodles may dry out.
• Cover the top noodles completely. Any noodle edge that isn’t under sauce turns hard and crisp in the oven. Spread the last 2 cups of sauce right to the corners.
• Tent the foil. Arch the foil or spray the underside lightly so it doesn’t pull the cheese off when you uncover the dish.
• Check the center. The edges bubble first. The lasagna is done when the middle is bubbling too and reads 165°F, since the chicken is being reheated.
• Don’t skip the rest. Cut too soon and the sauce runs across the plate. After 15 minutes, the pieces hold their layers.

Variations and Substitutions

• Frozen broccoli: Use a 16-ounce bag of frozen florets. Thaw them, pat them very dry, cut any large pieces to 1 inch, and skip the blanching step.
• Ricotta layer: For a richer lasagna, stir together 15 ounces of whole-milk ricotta, 1 egg, and a pinch of salt, and dollop half over the chicken in each of the two filling layers. The pan will be very full, so set it on the rimmed baking sheet as directed.
• Mushrooms: Brown 8 ounces of sliced mushrooms in a skillet until their liquid cooks off, then scatter them over the chicken.
• Cheese swap: Replace up to 1 cup of the mozzarella with shredded provolone or fontina for a nuttier flavor. Keep the Parmesan for saltiness and browning.
• Lighter milk: 2% milk works, but the sauce will be a little thinner. Add 1 extra tablespoon of flour to the roux.
• Gluten-free: Use gluten-free lasagna noodles and cook them according to the package. Thicken the sauce with a cup-for-cup gluten-free flour blend, and check that your broth is gluten-free.

What to Serve with Chicken Broccoli Lasagna

A rich, creamy lasagna goes best with something crisp and bright, like a green salad with a lemony vinaigrette, sliced cucumbers and tomatoes, or roasted carrots. For bread, try cheesy garlic breadsticks.

If you like chicken in a creamy Parmesan sauce, our chicken Alfredo is a quicker stovetop dinner in the same spirit. You’ll find more family-style mains in our dinner recipes.

Storage, Reheating, and Freezing

• Make ahead (unbaked): Assemble the lasagna, cover it tightly, and refrigerate it for up to 24 hours. Bake it cold from the refrigerator at 375°F, covered for 45 minutes, then uncovered for 20 to 25 minutes, until the center reads 165°F.
• Freeze unbaked: Let the sauce cool before assembling, and build the lasagna in a metal or disposable foil 9×13-inch pan. Don’t move a frozen glass dish straight into a hot oven, because it can crack. Wrap the pan in plastic wrap and then foil, and freeze for up to 3 months. Thaw it in the refrigerator for 24 to 48 hours and bake as for make ahead. To bake from frozen, remove the plastic, cover with foil, and bake at 375°F for about 1 1/2 hours, then uncover and bake 20 to 30 minutes more, until the center reads 165°F.
• Refrigerate leftovers: Refrigerate within 2 hours in airtight containers or in the covered dish. Leftovers keep for 3 to 4 days.
• Reheat: Microwave single pieces, covered, with a teaspoon of milk on top, in 1-minute bursts at 70% power until hot. For a larger portion, cover with foil and bake at 350°F for 25 to 30 minutes. Either way, reheat to 165°F in the center.
• Freeze baked: Cool the baked lasagna, cut it into portions, wrap each tightly, and freeze for up to 3 months. The white sauce may look a little looser or slightly grainy after thawing, but it comes back together as it reheats. Thaw overnight in the refrigerator, then reheat to 165°F.

Chicken Broccoli Lasagna FAQ

How many lasagna noodles fit in a 9×13 pan?

Twelve standard noodles make three layers of four: three laid lengthwise with a slight overlap, plus one trimmed to fill the gap at the short end. Cook a couple of extras because a noodle or two usually tears.

Can I use oven-ready (no-boil) noodles?

Yes. No-boil noodles absorb more liquid than boiled ones, so add 1/2 cup more milk to the sauce and keep the foil on for 35 minutes before uncovering. Most no-boil sheets are shorter, so check how many cover one layer of your dish.

Why did my white lasagna turn out watery?

The usual causes are wet broccoli, fresh (high-moisture) mozzarella, or cutting before the lasagna rested. Dry the blanched florets well, use low-moisture mozzarella, and give it the full 15 minutes before slicing.

Can I use raw chicken?

Not in this recipe. The chicken needs to be fully cooked before it goes in, because the lasagna isn’t in the oven long enough to cook raw chicken safely. Rotisserie, roasted, or poached chicken works well, and the finished lasagna should reach 165°F in the center.

Is this the same as chicken Alfredo lasagna?

Close, but the sauce is different. Alfredo is mostly cream, butter, and Parmesan. This sauce is thickened with a flour roux and made with broth and milk, so it stays creamy through a long bake without turning greasy, and it isn’t as heavy.

Can I make chicken broccoli lasagna ahead of time?

Yes. Assemble it up to 24 hours ahead and refrigerate it, or freeze it unbaked for up to 3 months. The Storage section has baking times for both.

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