Clean the cauliflower, cut out the hard stalk so that the head does not fall apart. Wash cauliflower. In a large pot, boil up plenty of salted water with milk and 2 tablespoons of lemon juice. Add the cauliflower (cabbage must be covered with water), if necessary weight down with a skimmer and cook for 15-17 minutes.
Peel and finely dice the onion and garlic. Clean, cut, seed and wash the chilli pepper. Cut the pod into rings. Heat oil in a pot. Sauté onion and garlic.
Stir in tomato puree, sweat it on and deglaze with tomatoes. Bring to the boil, puree finely, season with salt, pepper and sugar. Add chilli rings, simmer covered for 3-4 minutes. Lift the cauliflower out of the water and serve with sauce