Wash the potatoes thoroughly. Cook in boiling salted water for about 20 minutes. Drain, quench, peel and let cool off. Meanwhile roast pine nuts in a pan without fat until golden brown, take them out.
Peel the garlic and press it through a garlic press. Wash the basil, pluck the leaves from the stalks and chop coarsely, up to about 1/4. Puree 2/3 of the pine nuts, basil, garlic, parmesan and 8 tablespoons of olive oil in a blender.
Season with salt and pepper. Wash, clean and halve the tomatoes. Clean, wash and cut spring onions into rings. Heat 1 teaspoon of oil in a pan. Fry the spring onions in it at low heat.
Depending on the size, possibly halve the potatoes. Mix potatoes, spring onions, tomatoes and pesto and arrange in a bowl. Sprinkle with remaining basil and pine nuts.