Roast the pine nuts in a pan without fat. Put 1/2 teaspoon pine nuts aside for garnishing. Peel and halve the garlic. Pluck the basil leaves from the stalks, wash and pat dry.
Chop basil, parmesan, garlic, olive oil and remaining pine nuts in the universal chopper and season with salt and pepper. Wash, peel and dice the potatoes. Cook potatoes in vegetable stock for about 15 minutes.
Cut the tomatoes into pieces. After about 10 minutes add the beans and tomatoes. Wash spring onions, dab dry and cut into thin rings. Shortly before the end of the cooking time, add the spring onions to the stew.
Season stew with salt and pepper. Pour soup into plates and serve with pesto and pine nuts.