Heirloom Tomato Soup

This soup is delightful hot or cold and recently, depending on the weather, I have served it both ways.

1 Tablespoon olive oil
1 sweet onion, chopped
1 shallot, chopped
3 pounds heirloom tomatoes, skinned and chopped
3 cups of stock (chicken or vegetable)
1/4 cup ketchup
dash of hot sauce
1/4 cup fresh basil
1 Tablespoon balsamic vinegar
salt and pepper, to taste
1/4 cup cream, if desired

To skin the tomatoes, have a bowl of ice water ready. Heat a saucepan of water and dunk the tomatoes in the boiling water for about 1 minute, take out and plunge into bowl of ice water, after a few seconds take out the tomato and peel, chop (saving the juice) and set aside.
Heat the olive oil in a large saucepan over medium heat. Add onion and shallot and heat until soft. Add tomatoes, stock, ketchup and hot sauce. Heat gently, add salt and pepper, fresh basil and vinegar. Blend and adjust seasonings.
Can be served immediately or refrigerated and served cold.
Top with fresh basil or basil oil.