Step 1: Wash and slice green tomatoes into 1/4 to 1/3-inch thick rounds. Blot dry with paper towels to remove excess moisture.
Step 2: Prepare your dredging station: In a shallow dish, place 1 cup of plain all-purpose flour. In a second shallow dish, pour the buttermilk. In a third shallow dish, whisk together the cornmeal, 1/2 cup all-purpose flour, salt, black pepper, paprika, and cayenne pepper (if using).
Step 3: Dredge each tomato slice first in the plain flour, shaking off excess. This creates a dry surface for the buttermilk to adhere to.
Step 4: Dip the floured tomato slice into the buttermilk, ensuring full coating, then allow excess to drip off.
Step 5: Immediately transfer the buttermilk-coated slice to the cornmeal mixture. Press the mixture firmly onto both sides to ensure a thick, even coating. Place coated slices on a wire rack and let sit for 10-15 minutes to help the coating adhere.
Step 6: Heat 1/2 to 1 inch of oil in a large, heavy-bottomed skillet (preferably cast iron) over medium-high heat until it reaches 350-375°F (175-190°C).
Step 7: Carefully place a few coated tomato slices into the hot oil, without overcrowding the pan. Fry for 3-4 minutes per side, or until golden brown and crispy.
Step 8: Remove fried green tomatoes from the skillet with tongs and place them on a wire rack set over paper towels to drain excess oil. Season immediately with a sprinkle of salt.
Step 9: Repeat with remaining tomato slices, ensuring oil temperature stays consistent. Serve hot with your favorite dipping sauce.