Tomato and Basil Soup

1 lb. tomatoes, peeled, seeded and diced
1 medium onion, chopped
3/4 lb. potatoes, peeled and diced
3 cups vegetable stock
1/3 cup basil or lemon basil white wine or rice vinegar
1/4 cup fresh basil or lemon basil, minced
1 t. salt
1/2 tsp. freshly ground black pepper

In a large nonreactive saucepan, combine tomatoes, onion, potatoes, stock and vinegar. Cover and place over medium heat. Bring to a boil, reduce heat to low and simmer for 30 minutes, or until potatoes are very soft.

Pour the soup into a blender and puree. Stir in the basil, salt and pepper.