2 cups sugar
1 cup white vinegar
6 cups mangoes (4 to 5), peeled and cut in 3/4-inch pieces
medium onion, chopped (about 1 cup)
1/2 cup golden raisins
1/4 cup crystallized ginger, finely chopped
1 garlic clove,
1 teaspoon mustard seeds, whole
1/4 teaspoon red chili pepper flakes (hot)
Combine sugar and vinegar and bring to a boil, stirring until sugar dissolves.
Add remaining ingredients and simmer, uncovered, until syrupy and slightly thickened, 45 minutes to 1 hour.
Stir occasionally during cooking.
Pour into clean, hot jars.