Heat the olive oil in a pan and cook the onion, garlic and celery for about 10 minutes until the onion is soft and deep gold. Stir in the tomato purée and paprika and cook out for two minutes. Add the haricot beans, chopped tomatoes, stock and thyme and bring to the boil. Simmer for about 20 minutes until the liquid has reduced a little. Season. Serve either hot or warm.