Boil 1 litre of water. Add fat and about 1 teaspoon of salt. Stir in semolina. Continue stirring over low heat for 5 minutes. Cover and stir for another 15 minutes on
Stir from time to time. In the meantime, peel and quarter the onions. Wash the meat and dab dry. Cut each cutlet into 4 pieces. Put alternately 4 onion quarters and 4 escalopes on 1 skewer each.
Season with salt and pepper. Heat 2 tablespoons of oil in a large frying pan and fry the skewers for 6-8 minutes while turning. Peel garlic and press it through a garlic press. Heat 1 tablespoon of oil in a saucepan.
Sauté the garlic in it. Add the tomato paste and sweat briefly. Add the tomatoes and simmer for 5 minutes at low heat. Season to taste with salt, pepper and sugar. Serve polenta with the skewers and sauce.
Garnish with sage.