Heat oil in large nonstick skillet over medium heat until hot. Add onions and garlic; cook and stir 5 minutes or until onion is tender. Stir in vinegar, brown sugar, ginger and red pepper; cook and stir 2 to 4 minutes or until sugar is dissolved and mixture is thickened. Stir in tomatoes; cook 8 to 10 minutes or until sauce is thickened, stirring occasionally.
Remove from heat; stir in salt. Cool. Serve at room temperature.
Nutrition information per serving: 28.9 Calories; 8.1 Calories from fat; 0.9g Total Fat (0.1 g Saturated Fat; 0.6 g Monounsaturated Fat;) 0 mg Cholesterol; 75.9 mg Sodium; 4.9 g Total Carbohydrate; 0.6 g Dietary Fiber; 0.4 g Protein; 0.2 mg Iron; 0.2 mg NE Niacin; 0 mg Vitamin B6; 0 mcg Vitamin B12; 0.1 mg Zinc; 0.1 mcg Selenium; 3 mg Choline.