Beer Battered Onion Rings

Bahan-bahan (4 porsi)

• 2 large sweet onions
• 1 ½ cups all-purpose flour
• ¾ cup cornstarch
• 1 ½ teaspoon baking powder
• 2 teaspoons black pepper
• 2 teaspoons kosher salt
• 1 ½ teaspoons garlic powder
• 1 teaspoon onion powder
• ¼ teaspoon cayenne pepper
• 355 ml beer (1 can, divided *see note )
• 1 teaspoon salt
• ½ teaspoon black pepper