Boil the potatoes (or prepare jacket potatoes), cut into slices. Wash and slice the tomatoes. Cut the mozzarella into slices as well. Peel and chop the garlic. Wash and roughly chop the parsley and basil.
Preheat the oven to 220 ° C (top / bottom heat). Heat the oil in a pan or saucepan, briefly toss the herbs and chopped garlic in it, season with salt and pepper. Add the cream, bring to the boil.
Layer the potatoes, tomatoes and mozzarella in a baking dish. Pour the herb cream over it. Sprinkle with flakes of butter. Gratinate in the oven for 20 minutes.