Heat small saucepan over medium heat until hot. Add onion, garlic and ginger; cook and stir for 2 to 3 minutes. Add water and sugar; bring to a boil. Cook and stir 13 to 15 minutes or until reduced to 1/2 cup. Remove from heat; carefully stir in soy sauce, vinegar and mustard. Whisk in butter. Serve immediately.
Nutrition information per serving: 74.2 Calories; 23.4 Calories from fat; 2.6g Total Fat (1.7 g Saturated Fat; 0.7 g Monounsaturated Fat;) 6.8 mg Cholesterol; 278.9 mg Sodium; 12.3 g Total Carbohydrate; 0.2 g Dietary Fiber; 0.8 g Protein; 0.2 mg Iron; 0.1 mg NE Niacin; 0 mg Vitamin B6; 0 mcg Vitamin B12; 0.1 mg Zinc; 0.3 mcg Selenium; 3.1 mg Choline.