Cream of Tomato Soup

2 Tbls butter
1 onion, chopped
2 Tbls. flour
1 quart tomato juice (for best results, puree fresh tomatoes)
Salt to taste
2 cups milk

In large saucepan, saute onions in butter over medium heat, until translucent. Remove from heat. Stir in flour so that no lumps remain, then slowly whisk in tomato juice. Return to heat and add salt to taste. Cook just to boiling point. Turn off heat. Let cool 10 minutes and then slowly stir in milk. Serve immediately.