Remove the skin from the potatoes, rinse and cook in salted water. Remove the peel from the shallots and dice finely. Remove the skin from the garlic and cut into thin slices. Rinse the basil, rub dry and pluck the leaves. Chop the tomatoes.
Dry roast the pine nuts, remove and set aside.
Heat 2 tablespoons of olive oil, sauté the shallots and garlic until translucent, then add the remaining oil and heat.
Drain the potatoes, pour the oil over them and now mash the potatoes coarsely. Stir in the pine nuts, tomatoes and basil and season with salt and freshly ground pepper. Round off with the juice of a lemon.