Tomato Soup

This recipe comes from my sister-in-law. My husband loves it...I don't care for it.

Tomato Soup:
1 Tbsp onion
1/4 cup butter
2 Tbsp sugar
2 cans diced tomatoes
9 oz chicken broth
pinch baking soda
2 cups table cream
In a large saucepan, saute the onions in butter and sugar until opaque. Add the tomatoes, broth, and baking soda. Bring to a boil and turn down to a simmer, covered, for 1 hour. Add cream and serve hot.