Clean the cauliflower, cut into florets and wash. In a large pot, boil up plenty of salted water with milk and lemon juice. Add the cauliflower and cook for 10-12 minutes
Peel and finely dice the onion and garlic. Heat the oil in a pot. Sauté onion and garlic in it, dust with approx. 1/2 tsp. chilli powder and steam briefly.
Stir in the tomato paste, sweat it on and deglaze with tomatoes. Bring to the boil, puree finely, season with salt, pepper and sugar, cover and simmer for 3-4 minutes. Drain the pepperoni, cut into rings, stir about 2/3 into the sauce, season again. Lift the cauliflower out of the water, serve with sauce, dust with chilli powder and sprinkle with remaining pepperoni rings