For the remoulade sauce:
- 1/2 cup mayonnaise, such as Duke’s
- 2 tablespoons freshly squeezed lemon juice
- 1 medium scallion, finely chopped (optional)
- 1 tablespoon finely chopped fresh parsley leaves
- 1 tablespoon whole-grain or Creole mustard
- 1/2 teaspoon paprika
- 1/2 teaspoon hot sauce, such as Louisiana or Tabasco
- 1/4 teaspoon garlic powder
- 1/4 teaspoon kosher salt
- Pinch cayenne pepper
For the tomatoes:
- 2/3 cup instant flour, such as Wondra, divided
- 1 1/2 teaspoons kosher salt
- 3/4 teaspoon paprika
- 3/4 cup buttermilk
- 1 large egg white
- 1 1/2 teaspoons hot sauce, such as Louisiana or Tabasco
- 3/4 cup finely ground cornmeal
- 3 unripe green tomatoes (about 1 1/2 pounds total), cut into 1/4-inch thick slices
- 1/2 cup canola oil
- Make the remoulade sauce. Whisk all of the sauce ingredients together in a small bowl until combined. Cover and refrigerate until ready to serve.
- Season the flour. Stir 1/3 cup of the flour, salt, and paprika together in a wide, shallow bowl or pie plate.
- Make the wet mixture. Whisk the buttermilk, egg white, and hot sauce together in second wide, shallow bowl.
- Prepare the cornmeal. Stir the cornmeal and remaining 1/3 cup flour together in a third wide, shallow bowl.
- Bread the tomato slices. Fit a wire rack inside a rimmed baking sheet. Dip each tomato slice in the flour mixture, followed by the buttermilk mixture, and finally the cornmeal mixture.
- Set the cornmeal coating. Place the breaded tomato slices on the rack in a single layer. Let sit so the coating sets while the oil heats.
- Heat the oil. Heat the oil in a large cast iron skillet over medium-high heat until shimmering, about 5 minutes. The oil should sizzle immediately if you sprinkle flour into it.
- Fry the tomatoes. Carefully add 4 to 5 tomato slices and fry until golden-brown, 3 to 5 minutes per side. Transer the fried tomatoes to a paper towel-lined plate. Fry the remaining tomato slices.
- Serve warm the remoulade sauce. Serve the tomatoes immediately with the remoulade sauce.
Make ahead: The remoulade sauce can be made up to 2 days in advance. Fried tomatoes are best eaten immediately after frying.
Storage: Refrigerate leftover remoulade sauce in an airtight container for up to 2 days.