In a bowl, combine seasoning, water, soy sauce, and lime juice. Set aside.
Cut peppers into thin strips. Chop any large broccoli florets into bite-sized pieces.
Heat oil in Wok over high heat. Add peppers and broccoli. Stir-fry 1 min. Add shrimp, cooking 2 min, until they start to turn opaque (they will not be cooked through at this point).
Add mango and reserved seasoning mixture. Cook until mango is heated through and sauce is reduced, 2–3 min.
In a small bowl, whisk corn starch and cold water. Add to wok, stirring until sauce is slightly thickened. Serve with rice, if desired.