In a small bowl combine cornstarch, sugar and ginger.
Stir in orange juice, soy sauce and garlic; mix well until blended. Set aside in nonstick skillet or wok.
Stir-fry carrots, broccoli and cauliflower in 3 teaspoons of oil for 4-5 minutes
Add in mushrooms, peas and remaining 1 teaspoon oil; stir-fry vegetables for 3 minutes. Stir in orange juice mixture and bring to a boil over medium high heat. Stir vegetables and liquid mixture and cook until thickened.