Sprinkle with crushed red pepper, if using, and let stand for 5 minutes before serving.

Remove the foil and bake until the cheese is browned on top, about 10 minutes.

Cover with foil and bake until the rolls are heated through and the sauce is bubbling, about 20 minutes.

Position an oven rack to the middle position and preheat the oven to 425 degrees F.

Spoon the remaining pesto-bechamel sauce over the lasagna rolls and sprinkle with the remaining mozzarella and Parmesan.

Repeat with the remaining noodles and ricotta mixture.

Starting with a short end, roll each noodle up. As you make the rolls, transfer them to the prepared baking dish seam-side down.

Lay half of the cooked lasagna noodles on a clean work surface and spread 1/3 cup of the egg-ricotta mixture evenly over each.

Drain well and rinse with cold water. Lay in a single layer on a baking sheet.

Cook the lasagna noodles 1 minute longer than the package directions for al dente.

Bring a large pot of salted water to a boil.

Spread 1/4 cup of the pesto-bechamel sauce from the saucepan on to the bottom of the dish.

Brush a 13- by 9- inch baking dish with oil.

Stir pesto into the slightly cooled bechamel sauce.

Allow the bechamel sauce in the saucepan to cool slightly.

Cook, stirring frequently, until the sauce thickens and is the consistency of a thin gravy, 6 to 8 minutes.

Whisk milk, a large pinch of salt and a few grinds of pepper into saucepan.

Add flour to the saucepan and cook, stirring, for 2 minutes until lightly toasted.

Melt butter in a medium saucepan over medium heat.

Beat the egg in a large bowl and then stir in the rest of the ingredients.