Combine 3 tablespoons teriyaki sauce, peanut butter, water, red pepper and ginger. Cook vermicelli in salted boiling water according to package directions; drain and rinse. Toss vermicelli with peanut butter mixture to coat well.
Cut steak into 1/8-inch thick strips. Add remaining 2 tablespoons teriyaki sauce to beef strips; toss to coat evenly.
In a large nonstick skillet or wok, heat oil over medium-high heat until hot. Add beef (1/2 at a time) and stir-fry 1 to 2 minutes or until outside surface is no longer pink. (Do not overcook.) Add to noodles; toss lightly. Sprinkle with chopped cucumber.
Nutrition information per serving: 444 Calories; 151.2 kcal Calories from fat; 16.8 g Total Fat; 3.7 g Saturated Fat; 0.4 g Trans Fat; 5.2 g Polyunsaturated Fat; 5.6 g Monounsaturated Fat; 70 mg Cholesterol; 952 mg Sodium; 37.2 g Total Carbohydrate; 2.1 g Dietary Fiber; 34.5 g Protein; 3.6 mg Iron; 455 mg Potassium; 11.1 mg Niacin; 0.6 mg Vitamin B6; 1.5 mcg Vitamin B12; 5.1 mg Zinc; 31.2 mcg Selenium; 109.6 mg Choline;