- Combine teriyaki sauce and sugar in measuring cup, stirring until sugar dissolves.
- Remove 3 Tbsp. of mixture and pour over shrimp in large plastic food storage bag. Press air out of bag; close top securely. Turn bag over several times to coat pieces well. Marinate 15 minutes.
- Meanwhile, add enough water to remaining teriyaki sauce mixture to measure 2/3 cup; blend in cornstarch.
- Heat oil in large skillet over medium-high heat; add shrimp and sauté 2 minutes. Add teriyaki sauce mixture; cook, stirring, about 1 minute, or until sauce boils and thickens slightly.
- Spoon shrimp and sauce over rice in large individual serving bowls. Serve vegetables on top of rice or on the side, if desired.