Trim, wash and cut the broccoli into florets. Cook in boiling salted water for 6-8 minutes. Peel and halve the onion and cut into thin wedges. Wash the tomatoes, cut in half and cut into wedges.
Heat the oil. Fry the onions in it. Add the tomatoes and sauté for about 5 minutes while turning. Stir in tomato paste. Dust with flour and sweat. Deglaze with 3/8 liter of water and carrot juice, bring to the boil, stir in the granulated stock. Bring to the boil while stirring and simmer for about 5 minutes. Season to taste with salt and pepper.
Put the broccoli and tomato sauce in a greased baking dish. Rub the cheese over it. Baked for 15-20 minutes at 200 degrees.