Prepare all the ingredients.
Cut the red peppers in two...
...place them on a grid, skin side on top...
...and grill for 10 minutes in hot oven until skin is black.
Remove the skin using the tip of a knife. Slice in thin strips.
Cut the eggplants in 1 cm thick slices.
Blanch them for one minute...
...and drain them on paper towel.
In a saucepan, the onion and chopped garlic in oil.
Add herbs of Provence and minced button mushrooms.
Cook one minute.
Add crushed tomatoes, beans, Espelette pepper, salt and pepper. Simmer for 15 minutes uncovered.
Dip the lasagna noodles in warm water to soften them...
...then place a layer on the surface of a gratiné pan.
Spread half of the vegetable mixture on the noodles.
Cover with another layer of noodles.
Coat with cheese sauce...
...and sprinkle with a mix of cheddar and parmesan.
Bake 45 minutes in hot oven.
Cheese Sauce: Make a white roux using butter and flour.
Add warm milk to cooled white roux...
...and whisk.
Add the ricotta...
...until you obtain a creamy preparation.