Thaw the spinach. Fry the mince in the oil until crumbly while stirring. Peel and dice the onions and garlic, add to the mince and fry with them. Stir in tomatoes and tomato paste. Let it boil down thickly. Season with salt, pepper and rose paprika.
Sweat the flour in the fat. Deglaze with milk and stock. Simmer. Melt 75 g cheese in it and season with salt, pepper and nutmeg. Season the spinach with salt and nutmeg as well.
Spread some of the mince into a large baking dish. Layer 1/3 of the lasagne sheets, the rest of the mince, 1/3 lasagna sheets and the spinach. Pour half of the sauce on the spinach and cover with the remaining lasagne sheets. Pour the rest of the sauce over it. And spread the rest of the cheese over it.
Bake in the preheated oven at 200 ° C for approx. 50 minutes.