Peel the potatoes, wash them, chop them and boil in water to which you've added 1 vegetable broth cube. Then mash them with butter and milk. Add salt.
Boil the chicken legs and debone them.
Braise the mushrooms. Add the leeks. Once the mushrooms and leeks are nearly ready, add the torn to pieces chicken meat and the mushroom broth.
Lastly, add in the processed cheese and spices. Stir for a few min. on low heat and remove from the stove.
Lay out 1/2 the mashed potatoes in a slightly oiled tray. Put the filling with chicken on top. Distribute mashed potatoes again and sprinkle with grated cheese.
Bake the dish in a preheated 428°F (220 °C) oven until the cheese gains a golden crust.