Wash and peel the potatoes and cut them into thin slices. Wash and clean the sugar snap peas and drain well in a colander. Peel and chop the onion and garlic. Wash and clean the tomatoes and cut into bite-sized pieces, as well as the mozzarella.
Heat the oil in a pan and fry the potatoes for about 5 minutes. Add the snow peas and fry with the potatoes for another 5 minutes or until the potatoes are cooked. Then season with pepper, salt and granulated vegetable stock. Remove the pan from the stove and set aside.
Mix the tomatoes, mozzarella, onions and garlic with the vinegar. Add the lukewarm potatoes and snow peas straight from the pan with the oil to the tomato mixture, mix everything together and season to taste before serving.