• Slice tomatoes into 1/4-inch thick rounds.

To Make Breading Mixture:

• Whisk egg and buttermilk together in a shallow bowl.
• Scoop 1/4 cup flour onto a medium plate. 
• To a second medium plate add remaining flour, cornmeal, salt, pepper and cayenne; combine thoroughly with fork or small whisk.

To Bread Tomatoes:

• Dredge a tomato slice in plain flour, shaking off any excess; dip in egg mixture; dredge in cornmeal mixture until evenly coated and transfer to plate. Repeat with remaining tomato slices.

To Fry Green Tomatoes:

• Line a plate with paper towels; set aside.
• In a heavy skillet (ideally a cast iron skillet) heat 1/4-inch of high heat oil to 375°. (It's important for the oil to be very hot to keep tomatoes from absorbing it. Be sure to reheat between batches!) Carefully place tomatoes into hot oil and cook 1 1/2 to 2 minutes per side, until golden brown. Transfer to paper towel lined plate (keeping tomatoes in a single layer so they don't get soggy) and sprinkle with flaky sea salt. Repeat with remaining tomatoes. Serve hot.