Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 3). Clean, wash and slice the mushrooms. Clean and wash spring onions and cut them diagonally into rings. Halve liver cheese slices.
Heat the oil in a pan. Fry the meat loaf on each side over medium heat, remove. Fry the mushrooms in hot frying fat until golden brown. Add spring onions and fry briefly. Stir in sour cream and season everything with salt, pepper and thyme.
Toast bread in the toaster until golden brown and place on a baking tray lined with baking paper. Place Leberkäse on top. Spread the onion and mushroom mixture on top. Cut soft cheese into slices and place on top.
Sprinkle Gouda over it. Bake the toasts in a hot oven for about 10 minutes.