Dab meat dry and cut into 12 pieces. Clean and slice the mushrooms and side mushrooms. Pour the stock sponges onto a sieve and let them drain. Peel and finely chop the onion.
Heat the oil in a pan. Brown the meat on both sides for about 1 minute, remove and season with salt and pepper. Sauté the onion, mushrooms and herb side dishes in the frying oil for approx. 3 minutes.
Add the stock sponges and fry for about 2 minutes. Add stock and cream, bring to the boil. Stir in sauce thickener and bring to the boil. Season to taste with salt and pepper. Layer the meat in an ovenproof dish, add the cream of mushrooms.
Grate the cheese finely and sprinkle over it. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 8 minutes. Homemade mashed potatoes taste good with it.