Rosemary-Brined, Buttermilk Fried Chicken

INGREDIENTS

• 8 chicken legs, drumsticks and thighs separated
• 4 1/2 cups/1 liter water
• 1 lemon, quartered
• 2 cups/480 milliliters buttermilk
• 2 tablespoons baking powder
• 2 tablespoons fine sea salt
• Oil for deep-frying
• 5 or 6 branches rosemary, each 4 to 5 inches/10 to 12 centimeters long
• 3 tablespoons freshly ground black pepper
• 4 garlic cloves, smashed with the flat side of a knife
• 2 tablespoons paprika
• 1 small onion, thinly sliced
• 2 teaspoons cayenne pepper
• 8 chicken wings, wing tips removed
• 1 teaspoon vegetable oil
• 3 cups/420 grams all-purpose/plain flour
• Kosher salt