• Melt butter in a saucepan over medium heat, then saute onions until soft. Add remaining ingredients, cover and simmer for 20 minutes. Uncover, bring to a boil until it is reduced by 1/3. Allow to cool, strain to remove onion pieces, then freeze in 1-2 cup portions (or whatever portion size you find most convenient).

To use from freezer

• Either thaw in refrigerator or place sealed container in hot water. Then heat in saucepan or microwave, then use.