For the lasagna, dice onions and sauté in fat in a large pan. After a few minutes, add greens and mushrooms. Then add minced meat and sprinkle with spices.
Turn and break up the meat over medium heat until the mince is completely broken down and browned on each side. Add ketchup and water until you have an orange-red soup. Bring to a simmer and stir until the consistency is no longer runny.
For the bechamel sauce, place butter and flour in a high saucepan, heat and add milk. Cook until the consistency is creamy. If it gets too thick, thin it a little with water.
Grease the lasagna mold and line it with sheets of dough. Cover with bechamel sauce, then fill with a layer of minced meat and then cover with cheese. Repeat other layers in the same order.
For the last layer, take only pastry sheets, bechamel sauce and cheese. For a crispy cheese lid, cut the cheese into slices and place them without gaps. Let the lasagna sit for 2-3 hours and then bake for 45 min at 200°.
If you prepare the mince for the lasagna the day before, you will save time and the flavor will be more intense.