Combine marinade ingredients. Add shrimp and let stand 15 min.
Place cornstarch in a bowl and gradually add chicken broth, stirring until cornstarch dissolves. Add vinegar, sugar, and 2 Tbsp. soy sauce.
Heat a wok or large, heavy skillet. Add shrimp with marinade, onions, snow peas, and pepper. Stir fry until shrimp is pink, about 3 min. Add cornstarch mixture and stir fry until sauce thickens., about 1 min. Serve with rice.