COMBINE corn starch, flour, baking powder, garlic salt, onion powder, black pepper and cayenne pepper in a medium bowl. Add water and egg; stir until mixture is smooth.
HEAT 3 to 4 inches of oil in a deep pot over medium heat to 350°F.
DIP vegetables into batter, stirring batter occasionally. Fry a few vegetables at a time, turning once, 2 to 3 minutes or until golden brown and crisp.
DRAIN on paper towels. Serve immediately.
Recipe variation: 1 1/2 pounds raw, peeled shrimp can be substituted for the vegetables.