- Cut beef across grain into thin slices. Combine 1 Tbsp. cornstarch with soy sauce, sugar and garlic in small bowl; stir in beef to coat. Let stand 15 minutes.
- Meanwhile, blend remaining 1 Tbsp. cornstarch with 1 Tbsp. water in small bowl. Combine ponzu and 1/4 cup water in another bowl.
- Heat 1 Tbsp. oil in wok or large skillet over high heat until hot. Add beef and stir-fry 1 minute; remove.
- Heat remaining 1 Tbsp. oil in same pan. Add onion and crushed red pepper; stir-fry 1 minute. Add red bell pepper; stir-fry 2 minutes. Add mushrooms; stir-fry 1 minute.
- Stir in cornstarch and ponzu mixtures. Cook, stirring, until sauce boils and thickens. Add basil and beef; cook and stir until basil wilts.
- Spoon over rice and sprinkle with peanuts. Serve immediately.