Bring milk, 250 ml water, 1 teaspoon salt and 50 g fat to the boil. Stir in polenta and let it swell for 10 minutes. While still hot, spread on 1/3 of a baking tray lined with baking paper and let it cool down.
Meanwhile roast the pine nuts in a pan without fat, remove them. Carve tomatoes crosswise, blanch with boiling water, rinse and peel the skin. Cut the tomatoes into pieces. Peel onions and garlic and dice finely.
Wash the rosemary and remove the needles from 2 stems. Heat 1 tablespoon of oil in a saucepan. Sauté the onions, garlic and rosemary. Add tomato pieces and simmer for about 5 minutes. Season with salt and pepper.
Wash the cherry tomatoes, dab dry. Heat 1 tablespoon of oil in a frying pan. Fry the cherry tomatoes briefly, sprinkle with sugar and allow to caramelize slightly. Deglaze with vinegar and stock, bring to the boil and add to the tomato sauce.
Sprinkle pine nuts over it. Cut the polenta into rhombs. Heat 2 tablespoons of fat in a frying pan and fry the polenta rhombs in it for about 3 minutes on each side until golden brown. Arrange the rhombs with tomato sauce on plates.
Garnish with the rest of the rosemary.