Salt tomato slices and rest on paper towels 10 minutes, then pat dry.
Mix almond flour, flaxseed meal, smoked paprika, cayenne, salt, and pepper in a shallow bowl.
Dip tomato slices in beaten egg, then press into the flour mixture, coating both sides.
Heat avocado oil in a skillet over medium-high heat. Fry slices 2–3 minutes per side, until golden. Drain on paper towels.
Whisk together mayonnaise, ketchup, hot sauce, Worcestershire, and garlic for the comeback sauce.
Serve fried tomatoes warm with comeback sauce for dipping.