This is the MOST IMPORTANT STEP! Line the tomato slices on a paper towel and pat dry on both sides. Season the slices with kosher salt on both sides and let them sit for 20 minutes. This draws out the moisture, which gives you crunchy tomatoes. While they sit, prepare the remoulade (below) and the batter ingredients.
In a mixing bowl, whisk together the flour, paprika, mustard powder, 1/2 tsp kosher salt and pepper. In another mixing bowl, whisk the 2 eggs to create an egg wash. Finally, in a 3rd mixing bowl, whisk together the cornmeal, panko bread crumbs and 1/2 tsp kosher salt. Line these up in the order of flour mixture, eggs, then cornmeal mixture. Place a sheet pan or plate near the cornmeal plate.
Dry the tomato slices off again. Designate one hand as your "dry batter" hand and the other as your "wet batter" hand. One at a time, dip the tomato slices into the flour with your dry batter hand. Dust off excess. Then dip in the egg wash with your wet batter hand, until fully coated. Finally, switch back to your dry batter hand and dip into the cornmeal mixture and make sure the tomato slice is coated in cornmeal crumbs on all sides. Repeat with all the slices, then spritz in an oil of your choice.
Air fry at 400 degrees for 10 minutes, then flip and air fry for another 5-10 until deep golden brown and crunchy. Do not remove when they are light golden brown. Every air-fryer is different, so it may take you longer to achieve deep golden brown results. Serve immediately for the ultimate crunch!