Rinse shrimps, defrost. Wash or peel potatoes thoroughly, cut in half or quarters. Peel and chop the onion. Wash the sage and, except for a little bit, chop finely
Heat the oil in a large frying pan. Fry the potatoes for 15-20 minutes until golden brown. Add the onions and sage to the potatoes 10 minutes before the end of the frying time. Season with salt and pepper
Dab the shrimps dry. Put 4-5 prawns on skewers each. Heat herb butter in a second pan. Fry the prawns for about 3-4 minutes, turning them over. Season with salt and pepper
Drain mozzarella, dice. Add the cheese to the potatoes shortly before the end of the frying time and let it melt. Arrange skewers on top
Drink: cool white wine