Finely chop the onion and carrot, and sauté them with the canned tomatoes in a deep pan. Add the minced meat and stir. Season with black pepper, red pepper, and salt. Let it simmer.
In another pot, prepare the Béchamel sauce. Heat the oil and fry the flour. Add the milk, stirring until the sauce thickens. Season with black pepper and salt, then remove from heat.
Layer the lasagna sheets in a baking dish, starting with a layer of sheets, followed by the tomato sauce and Béchamel sauce. Repeat until all ingredients are used, finishing with sheets covered only with Béchamel sauce.
Generously sprinkle with grated cheese and bake for about 20-25 minutes.