In a saucepan, saute onion in 1 Tbsp olive oil until tender. Add water (or wine), frozen orange juice concentrate, soy sauce, spices & cubed guava paste. Bring to a boil; reduce the heat slightly & continue to boil gently until mixture reduces slightly. In a cup, combine cornstarch & water & add to sauce continuing to cook about 2-3 minutes more. Taste to see if any spice adjustments are needed.