1. Preheat the oven to 400°F. Arrange the bacon on a rack on a rimmed baking sheet and bake for 12 to 15 minutes or until crisp. Drain on paper towels.

2. Meanwhile, slice the tomatoes 1/3 inch thick. Lightly salt them on both sides and set them aside for 10 minutes; pat them dry. Combine the mayonnaise, basil, lemon zest, ¼ teaspoon salt, and 1/8 teaspoon pepper in a blender and puree. Pulse the bread in a blender or food processor to make 2 cups fresh bread crumbs.

3. Spread out the flour and bread crumbs in separate pie plates lined with wax paper or parchment; beat the egg in a bowl. Season the catfish fillets with salt and pepper to taste; working with 1 fillet at a time, toss them in the flour, lifting the wax paper on both sides to move them around; shake off the excess flour. Dip them into the egg, letting the excess drip off, and finally into the crumbs, shaking off any excess.

4. Heat 2 tablespoons olive oil in a large nonstick skillet over medium heat until hot. Saute the catfish for about 5 minutes per side or until golden and just cooked through. Add the remaining 2 tablespoons olive oil when you turn the pieces.

5. Toast the bread. Place 4 slices on serving plates and spread the top sides with some of the mayonnaise mixture; top each with lettuce, bacon, tomatoes, and a catfish fillet. Spread one side of the remaining toast slices with the mayonnaise mixture and place them, mayo side down, on the sandwiches. Cut each sandwich in half and serve.