- Score both sides of trout with 3 diagonal slashes 1/4 inch deep and 1 inch apart. Combine cornstarch, salt and pepper; coat trout with mixture, shaking off excess.
- Heat 2 Tbsp. oil in large nonstick skillet over medium heat until hot. Add trout; cook 6 to 7 minutes.
- Turn trout over; pour remaining 1 Tbsp. oil around edges of pan. Cook 6 to 7 minutes longer, or until fish flakes easily when tested with fork.
- Meanwhile, blend sweet & sour sauce, 6 Tbsp. water and sugar in small saucepan.
- Remove trout to serving platter and keep warm.
- Heat sweet & sour sauce mixture over medium-high heat until hot, stirring occasionally.
- To serve, pour half of sauce over trout and sprinkle green onions over fish and sauce. Pass remaining sauce.