1. Prepare the rémoulade: Combine all the rémoulade ingredients in a small bowl. Set aside until ready to serve. Fill a deep-fryer or large, heavy pot two-thirds of the way (no more than that) with the oil and heat to 350°F.
2. Lay tomato slices out on a plate and prepare a dredging station: Lining up three rimmed dishes, mix the spice blend in the first dish, the eggs and buttermilk in the second dish, and the panko and cornmeal in the third dish. Place both sides of each tomato in the spice blend first, then in the wet mixture, and then in the coating.
3. Place the dredged tomatoes in the hot oil. Fry until golden brown on both sides, flipping after about 30 seconds on the first side. Transfer the fried tomatoes to a cooling rack or paper towels to drain.
4. Serve on a large platter with the rémoulade.
Variation: Fried Okra with Cajun Remoulade
When you talk about the South, you have to talk about okra. Many may be worried by the ooey-gooeyness or the natural “stickiness,” but I promise you that this southern classic will become a family favorite. Following the recipe, simply replace the tomatoes with about 2 pounds of okra, sliced into ½-inch pieces.