Cool Tomato Soup

Cool Tomato Soup
2 tbsp. olive oil
1 onion, chopped
3 cups tomatoes, peeled and seeded
1 cup chicken stock
1 tbsp. lemon juice
1 cup plain yogurt
2 tbsp. fresh parsley, chopped
2 tbsp. fresh basil, chopped
1/2 tsp. salt
1/4 tsp. fresh ground pepper

Heat oil over medium heat in saucepan. Cook onion for 3–4 minutes or until soft. Add tomatoes and cook for 2 minutes. Pour in stock, bring to boil over high heat. Lower heat and simmer, covered for 10 minutes or until tomatoes are tender. Let cool.
In blender, process tomato mixture until smooth. Add lemon juice. Whisk yogurt in mixing bowl until smooth, whisk into tomato mixture. Whisk in parsley, basil, salt and pepper. Serve chilled, garnish with a swirl of yogurt.