Clean and wash the spinach. Peel and finely dice onions and garlic. Fry garlic and half of the onions in 1 tbsp. hot oil. Add the spinach and let it collapse. With salt and pepper
Wash and halve the tomatoes. Wash sage, dab dry and chop finely. Dab cutlets dry and tap flatter. Season with salt and pepper. Cover with 2 slices of pancetta. Spread spinach on top.
Roll up from the long side. Cut the rolls into 3 pieces and fix them with wooden skewers.
Boil up milk, 1⁄2 l water, butter, 1 teaspoon salt, pepper and 1 pinch of nutmeg. Stir in polenta, cover and let it swell for about 15 minutes at low heat, stirring from time to time.
Fry the rolls in portions in 2 tablespoons of hot oil all around. Remove and briefly sauté the rest of the onion, tomatoes and sage in the cooking fat. Add stock and bring to the boil. Add the rolls, cover and stew for about 5 minutes.
Stir the starch with 1 tbsp. water until smooth, thicken the sauce as desired. Season to taste with vinegar, salt and pepper. Arrange everything.
Drink tip: white wine, for example an aromatic Gavi di Gavi.