Halve the garlic cloves for the bechamel sauce, wrap in aluminum foil and cook in the oven at 200 degrees for about 20 minutes, then cut the cloves into small pieces. Cook the lasagne plates in hot water together with the saffron al dente and place them on a cloth to dry off.
Cut the zucchini into small slices. First fry the onion in a hot pan with olive oil, then let the zucchini stew for a few minutes. Add the mushrooms and peas and simmer in the covered pan for about 10 minutes. Season the vegetables with lemon juice, salt, pepper and oregano.
Melt the butter in a saucepan. Carefully stir in the flour, pour in the boiling milk and bring to the boil. Season the sauce with garlic, parmesan, salt and pepper. The bechamel sauce is now ready.
Spread out a layer of lasagne sheets in an oiled baking pan and cover each with a layer of the béchalmel sauce and the mushroom vegetables. Spread out another layer of lasagne and top with the bechamel sauce and vegetables. The last layer should be the lasagne sheets.
Cover the lasagna with aluminum foil and bake it in an oven preheated to 200 degrees for about 20 minutes. Reduce the temperature to 180 degrees, remove the foil and bake for another 15 minutes. Let the lasagna rest for about 5 minutes and serve warm.