Peel and chop the onions. Heat the oil. Fry the chopped onions in it until crumbly. Fry onions and season. Stir in tomatoes with juice and tomato paste. Mash tomatoes. Let it boil down for about 10 minutes. Season with salt, pepper, paprika and sugar
Clean, wash and finely dice the vegetables. Steam in hot fat for about 5 minutes. Sweat flour in it. Deglaze with 1/4 l water and milk while stirring. Bring to the boil, stir in broth. Let simmer for about 5 minutes. Season to taste
Grate cheese. Pour 1/4 of the sauce into a large greased casserole dish (approx. 25 x 30 cm)
Place the lasagne plates on top. Add half the chopped mass and 1/4 of the béchamel sauce. Cover with 6 lasagne sheets. Fill in the rest of the minced meat and 1/4 béchamel sauce. Cover with the remaining pasta and finish with the rest of the sauce and cheese.
Bake in a hot oven (electric cooker: 200 °C / convection oven: 175 °C / gas: level 3) for approx. 45 minutes. Wash and chop the parsley and sprinkle over it