Guaranteed by Galanter's Kitchen

Adapted from Simply Recipes. It’s really tasty!

2 cups sugar
1 cup distilled white vinegar
6 cups mangoes (4 to 5), peeled and cut in 3/4-inch pieces
1 medium onion, chopped (about 1 cup)
1/2 cup golden raisins
1/4 cup crystallized ginger, finely chopped
1 garlic clove, minced
1 teaspoon mustard seeds, whole
1/4 teaspoon red chili pepper flakes (hot)

Combine sugar and vinegar in a 6 quart pot; 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.