Put all other ingredients in a saucepan and bring to the boil while stirring. Add the potato slices and bring to the boil briefly. Remove from the stove and pour the contents of the pot into a casserole dish.
Bake in a preheated oven at 200 ° C top / bottom heat for a good hour.
If the casserole gets too dark, slide it in one level deeper or cover it with aluminum foil.
Fits as a side dish with meat and vegetables, but also as a main course with a salad.