Peel onions and garlic. Peel and wash the carrots. Dice everything finely. Cut bacon into cubes. Heat oil in a large pan. Fry the bacon and minced meat in it thoroughly. Fry the carrots, garlic and half the onions briefly.
Season with salt, pepper, oregano and paprika.
Deglaze with tomatoes (including juice) and wine, crush tomatoes finely. Bring to the boil and simmer for about 10 minutes.
For the béchamel, heat 75 g fat in a saucepan. Fry the rest of the onions until transparent. Dust with flour and sauté briefly. Stir in milk, 1/2 l water and stock. Bring to the boil and simmer for 5-10 minutes, stirring frequently.
Season to taste with salt, pepper and nutmeg.
Finely grate the cheese. Spread some béchamel on the bottom of a large greased casserole dish. Layer 4 lasagne plates, 1/4 of the minced sauce, cheese and béchamel alternately, finishing with béchamel and cheese.
Spread 2 tablespoons of fat in flakes over it. Bake in the preheated oven (electric oven: 200°C/circulating air: 175°C/gas: level 3) for 45-50 minutes. Serve and garnish with oregano. Drink tip: dry red wine, e.g.