Peel and chop the onion. Fry with corn semolina in 1 tablespoon of hot fat. Add 1/2 l water and bring to the boil. Stir in broth and let it swell covered for about 15 minutes. Grate cheese. Take polenta off the stove. Stir in cheese and egg yolk, season. Spread into a flat casserole dish (approx. 15 x 20 cm) and cool down
Wash herbs, chop. Wash, quarter, seed and finely dice the tomato. Clean, wash and possibly chop the mushrooms
Turn out the polenta and cut it into about 12 rhombs. Fry in 1 tablespoon of hot fat until golden brown. Take out and keep warm
Fry the mushrooms in the frying fat until they are firm. Add approx. 1/8 l water and cream, bring to the boil and simmer for 3-4 minutes. Season. Stir in the herbs, except for a little bit. Arrange everything, garnish with tomato and other herbs