Peel and chop the onions and fry them in hot oil. Sweat the tomato paste briefly. Add tomatoes and juice, chop coarsely. Bring to the boil, season with salt and cayenne pepper. Drain corn and beans, add. Simmer everything open for about 10 minutes
For the béchamel sauce, sauté the flour in 2 tablespoons of hot fat. Stir in 600 ml water, cream and stock. Bring everything to the boil and simmer for about 5 minutes. Season to taste. Grate cheese
Grease the casserole dish (approx. 20 x 24 cm). Cover the bottom with some béchamel sauce. Alternately layer 3 lasagne dishes, vegetable sauce, béchamel sauce and cheese. Finish with béchamel sauce and cheese
Bake in a hot oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for approx. 50 minutes. If necessary, cover after approx. 30 minutes