1 cup finely chopped onion
3 cups butter, cubed
1 cup white sugar
2 1/2 teaspoons cream of tartar
2 teaspoons vanilla extract
1 teaspoon lemon juice
1 (2 liter) bottle lemon flavored carbonated beverage
1 cup sour cream
1 cup chopped fresh parsley
In a small saucepan, heat butter over medium heat. Stir in sugar and cream of tartar. To the mixture add lemon juice and lemon flavored carbonated beverage. Stirring constantly, cook and stir until mixture is thickened.
Once mixture has thickened, stir in sour cream and chopped parsley. Heat to desired dimension, stirring constantly. Serve hot or cold.