In small bowl combine cornstarch and water. Add chicken broth, sugar, vinegar, chili paste and soy sauce. Set aside. Heat oil in large nonstick skillet over high heat. Add garlic and ginger; saute for 30 seconds. Add chicken and cook until no longer pink, about 5-8 minutes. Add grapes and green onions; saute for 30 seconds. Restir the sauce mixture and pour into skillet. Stir until thickened, about 1 to 2 minutes. Remove from heat. Place chicken mixture in lettuce leaves; garnish with cilantro and cucumber, then roll up. Serve immediately.
Nutritional Stats: Calories 339; Protein 44g; Fat 6g; Calories from Fat 17%; Carbohydrates 27g; Cholesterol 99mg; Fiber 3g; Sodium 1341mg.