1. To make the remoulade, place the crushed crackers in a medium bowl and add the mayonnaise, chili sauce, horseradish, lemon juice, Creole mustard, paprika, cayenne pepper, garlic and scallions. Mix well to combine. Refrigerate at least 30 minutes, or until ready to use.
2. Line 2 rimmed baking sheets with paper towels. Lay the tomato slices on one sheet, sprinkle with salt and set aside for about 5 minutes to allow the tomatoes to release some liquid.
3. Whisk together the cornmeal and flour in a shallow dish. Combine the buttermilk and hot sauce in a separate medium bowl. Pat the tomatoes dry. Dip the tomatoes in the buttermilk, and then dredge each slice in the cornmeal and flour mixture. Place them back on the baking sheet. Set the other prepared baking sheet next to the stove.
4. Heat a large nonstick skillet over medium high heat. Add the oil and heat until the surface is shimmering. Add the tomatoes and fry in batches, turning once, until golden and crisp, about 2 minutes per side. Place each slice on the prepared baking sheet to drain. Sprinkle with the Cajun seasoning. Serve warm with the remoulade sauce for dipping.