Chinese Plum Sauce

8 cups plums, pitted, halved (3 pounds/1.5 kg)
1 cup onion, chopped
1 cup water
1 teaspoon gingerroot, minced
1 clove garlic, minced
3/4 cup granulated sugar
1/2 cup rice vinegar or 1/2 cup cider vinegar
1 teaspoon ground coriander
1/2 teaspoon salt
1/2 teaspoon cinnamon
1/4 teaspoon cayenne pepper
1/4 teaspoon cloves

In large heavy saucepan, bring plums, onions, water, ginger and garlic to boil over medium heat; cover, reduce heat to low and simmer, stirring occasionally, until plums and onions are very tender, about 30 minutes.

Press through food mill or sieve and return to clean pan; stir in sugar, vinegar, coriander, salt, cinnamon, pepper and cloves. Bring to boil, stirring; reduce heat to low and simmer until mixture reaches consistency of applesauce, about 45 minutes.

Fill and seal jars; process in boiling water bath for 30 minutes.

Makes about 4 cups