Wash the peppers well.

Cut the cap, remove the seeds and with a small knife remove the internal white ribs.

Cut them into strips not too thin, each strip should be as wide as your index finger.

Heat oil in a large nonstick skillet over medium heat.

Add the peppers and onion; season with salt and pepper.

Cook, stirring occasionally, until peppers are just tender, about 10 minutes.

Add chopped parsley and grated Parmigiano Reggiano cheese.

Blend the mixture by using a handheld immersion blender or a countertop blender until it is as rough or as smooth as you like it.

Spread a ladle of béchamel and pepper sauce and butter on the bottom of a rectangular baking pan about (13x 9 inches) in size.

Lay the lasagna sheets over the entire surface and season with the pepper sauce, grated Parmigiano Reggiano, and a few slices of provolone cheese and 2 tablespoons of béchamel sauce.

Cover with lasagna sheets and repeat the process above in layers until all the ingredients are used up.

Finish with a layer of lasagna seasoned with plenty of pepper sauce and sprinkle with Parmigiano Reggiano and béchamel sauce.

Bake in a preheated oven at 180°C (356°F) for about 30 minutes, until a delicious golden crust, is created on the surface.

Remove from the oven and let cool.