Plum Bar-B-Que Sauce

1/4 c  Onion; Chopped -- 1 small      16 1/2 oz Purple Plums; 1 cn *
1/4 c  Butter Or Margarine                 6 oz Frozen Lemonade; Thawed -- 1
1/4 c  Chile Sauce                              Cn
  2 ts Mustard -- Dijon-style

*  Plums should be drained, pitted and finely chopped.
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Cook onion in margarine in 2-quart saucepan stirring occasionally, until
tender, about 2 minutes.  Stir in remaining ingredients.  Heat to boiling;
reduce heat to low.  Simmer, uncovered, 15 minutes, stirring occasionally.
Makes about 2 cups of sauce.