Clean vegetables, peel and wash if necessary. Cut carrots, leek and fennel into slices, cabbage into strips. Bring the stock to the boil. Cook carrots for about 15 minutes, add cabbage and fennel after about 5 minutes, leek after 12 minutes. Drain the vegetables, catch the broth.
Peel and finely chop the onion. Heat 30 g fat in a pot, fry onion in it. Stir in flour, sweat briefly. Deglaze roux with 300 ml stock and milk while stirring, bring to the boil and simmer for about 5 minutes. Stir caraway into the sauce, season with salt and pepper. Put cabbage and fennel into a greased casserole dish (approx. 29 x 17 cm). Pour half of the sauce over it. Layer carrots and leek on top. Pour the rest of the sauce over it. Chop the toast finely.
Pour half of the sauce over it. Layer carrots and leek on top. Pour the rest of the sauce over it. Chop the toast finely. Fry in 10 g fat and sprinkle on the casserole. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 30 minutes. Serve with tomato sauce