¼ teaspoon cayenne pepper
Oil for deep-fryingInstructions
Cut onions into ½-inch slices; separate into rings. Place in a bowl; cover with ice water and soak for 30 minutes.
Meanwhile, combine egg, water, oil, and lemon juice in a bowl; mix well. In a separate bowl, combine flour, baking powder, salt, and cayenne pepper; stir into egg mixture until smooth.
Drain onion rings; dip each one into batter. Heat oil to 375° in a deep-fryer or electric skillet with 1 inch of oil. Fry a few at a time for one to two minutes per side until golden brown. Drain on paper towels. Keep onion rings warm in a 300° oven as the remainder of the batch is being fried.