Wash and chop the onions, sauté the onions in a pot with some butter, add the minced meat and sauté with salt, pepper and garlic
Add tomato puree and fill up with 1/2l water Add leek and cook for about 15 minutes
Melt the béchamel sauce 80 g butter in a saucepan, add the flour and let it sweat slightly while stirring constantly
Add milk bit by bit, stirring constantly with a whisk so that no lumps form Sauce with salt and pepper season to taste me after pouring if the sauce is too thick Grease the casserole
Bechamel sauce minced meat sauce grated cheese and lasagne alternately layer approx. 4-5 layers in the preheated oven at 200° approx. 30 minutes