Peel onion and garlic. Chop the onion finely, press the garlic through a garlic press. Wash the thyme, dab dry and chop except for a few stems for garnishing. Melt 15 g fat in a pot, fry onion and garlic in it. Add thyme and deglaze with milk and broth, season with salt and pepper, bring to the boil and stir in polenta bit by bit.
Cook over a low to medium heat while stirring to a thick mash. Put it into a greased, ovenproof dish. Clean and wash the peppers, zucchini and spring onion. Cut the bell pepper and zucchini roughly into pieces. Cut spring onion into fine rings. Clean and roughly dice the vegetable onion. Heat 20 g fat in a frying pan and fry the vegetables, except for the spring onions. Season with salt and pepper and spread on the polenta. Mix parmesan and spring onions and sprinkle over the vegetables. Spread the remaining fat in flakes on top.
Clean and roughly dice the vegetable onion. Heat 20 g fat in a frying pan and fry the vegetables, except for the spring onions. Season with salt and pepper and spread on the polenta. Mix parmesan and spring onions and sprinkle over the vegetables. Spread the remaining fat in flakes on top. Bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 20 minutes. Serve garnished with parsley and thyme