Use this as a topping for Grilled Sirloin Steak.
In a medium saucepan, heat oil over medium. Add onion, garlic, and ginger. Cook, stirring, until onion is softened, 5 to 7 minutes. Add tomatoes, vinegar, brown sugar, and raisins. Simmer, stirring occasionally, until thick and jamlike, 35 to 45 minutes. Cool completely.