For the stew, clean the mushrooms, wash if necessary and cut into slices. Peel onions and garlic and chop finely. Wash the thyme, shake dry and remove the leaves.
Heat the oil in a large pot. Fry the minced meat in it for about 8 minutes until finely crumbly. In the last 3 minutes fry onions, garlic and mushrooms. Season with salt, pepper and half the thyme. Dust with flour and sauté briefly.
Deglaze with stock and 400 ml water. Bring to the boil and simmer for about 10 minutes. Season to taste with salt and pepper.
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Cut a lid off each loaf of bread. Scoop out breads with a spoon. Make sure that the crust is not damaged.
Use bread leftovers for other purposes. For example, you can pluck the inside of the bread in crumbs, roast it in a pan and sprinkle it over the soup. Or you can also dry it and knead it with minced meat to make meatballs and grind it finely for breadcrumbs and keep it dry.
Fill sandwiches with stew. Cut the cheese into slices and spread on the breads. Bake in a hot oven for about 5 minutes. Serve and sprinkle with the rest of thyme. Serve the rest stew with it or refill.