PREPARE THE PASTA
Fill a large, deep pot with water and add 1/2 tablespoon salt. Bring to a boil.
Cook the lasagna noodles for about 5 minutes, until they are firm but flexible.
Remove from the boiling water and immediately cool in ice water to stop the cooking.

PREPARE THE CHICKEN
In a hot skillet with olive oil and butter, cook the garlic and onion until lightly golden.
Add the chicken, salt, and pepper, and cook through.
Add the flour and cook for a couple of minutes, stirring often so it doesn’t stick or burn.
Add the cream and let it thicken. Let cool.
Once the chicken mixture is cool, mix in the ricotta cheese.

ROAST THE VEGETABLES
Preheat the oven to 500° F (260° C).
On a baking sheet, toss all the vegetables and seasonings with the olive oil, except the salt.
Roast the vegetables in the oven for about 28 minutes, then let cool.
Add the salt and stir.

MAKE THE BECHAMEL SAUCE
In a pot, melt the butter.
Add the flour and cook over low heat for a couple of minutes, letting it turn slightly golden and smooth.
Gradually add the cold milk, stirring as it thickens.
Add the hot milk and continue stirring. The sauce should be creamy and smooth.
Cook the sauce for about 9 minutes to remove the raw flour taste.
Add salt and nutmeg.

Mix the Manchego cheese with the breadcrumbs and paprika.

ASSEMBLE THE LASAGNA
Mix the chicken with the roasted vegetables.
In a 14 x 9 x 1.5 inch (35 x 22 x 4 cm) lasagna pan, spread a little bechamel sauce on the bottom.
Add a layer of lasagna noodles, then a layer of the chicken mixture.

BAKE
Preheat the oven to 325° F (163° C).
Bake the lasagna for about 70 minutes, until the internal temperature reaches at least 150° F (66° C).
Let the lasagna rest for about 15 minutes. If it’s too hot, it may fall apart when serving, so resting is important.
Cut the lasagna into 8 portions.
Serve each portion on individual plates with a little bechamel sauce.