- Cut beef across grain into thin slices. Combine 1 Tbsp. each cornstarch and soy sauce with sugar, ginger and garlic; stir in beef. Let stand 15 minutes.
- Meanwhile, remove flowerets from broccoli; cut in half lengthwise. Peel stalks; cut crosswise into 1/8-inch slices.
- Combine 4 teaspoons cornstarch and remaining 3 Tbsp. soy sauce with 1-1/4 cups water.
- Heat 1 Tbsp. oil in large skillet or wok over high heat. Add meat and stir-fry 1 minute; remove from pan.
- Heat remaining 2 Tbsp. oil in same pan. Add broccoli and onion; stir-fry 4 minutes, or until vegetables are tender-crisp. Stir in meat and soy sauce mixture; bring to boil. Cook and stir only until sauce thickens.
- Serve immediately over rice.