Wash the potatoes and cook them in boiling water for about 20 minutes until al dente. Roast the pine nuts in a small pan without fat until golden brown, take them out. Put 1 tablespoon of pine nuts aside.
Wash the basil, dab dry, pluck coarsely, chop finely with the remaining pine nuts, approx. 4 tablespoons of oil and grated Parmesan cheese in the universal chopper. Season pesto with salt, pepper and a little lemon juice.
Drain the potatoes, rinse with cold water and peel. Drain the mozzarella. Wash the tomatoes, dab dry, cut in half and place in a bowl with the mozzarella and potatoes. Add pesto, mix, season with salt and pepper.
Pluck the ham roughly and fold in briefly. Arrange salad in a large bowl, sprinkle with remaining pine nuts and parmesan and garnish with basil.