sentence: heat some olive oil in a pot and cook some chopped onion in it sentence: add fresh chopped tomatoes and stir sentence: add salt and pepper and stir sentence: cook until the tomatoes to clapse and add tomato paste sentence: add some chicken stock and stir sentence: add some peeled and chopped potatoes to the soup sentence: cover the pot and cook until potatoes are soft sentence: add some fresh basil leaves and blend everything in the soup sentence: take out the soup and garnish with more basil leaves to serve