Peel the garlic, cut it in half, rub it into a fondue pot (fireproof ceramic!), fill it with the apple juice and let it boil, add the cheese while stirring and simmer on low heat until the quantity is uniform.
Mix 2 tsp. cornstarch with the juice of one lemon, thicken the fondue with it and continue to simmer on the stove. Finely grate the onion and fold it in.
Serve with: brown bread, tomato salad.