Peel the vegetables and onions. Cut into 3-4 mm thin slices. Peel the garlic cloves and slice them into wafer-thin slices.
Layer the vegetables according to type in the following order in the largest possible buttered casserole dish as follows: Potatoes - 1 onion - garlic - beetroot - 1 onion - pumpkin - garlic - potatoes. Salt each layer and season with freshly ground pepper, a little marjoram and nutmeg.
Mix the cream, milk and goat cream cheese so that the cheese dissolves completely. Pour over the vegetables. Sprinkle the gratin with flakes of butter and pour on the sherry.
Bake in a preheated oven at 180 ° C for about three quarters of an hour.