In a shallow dish, mix flour, salt, pepper and cayenne pepper together.
In separate shallow dish, beat eggs and milk together.
Pour bread crumbs into a third shallow dish.
Dredge tomato slices in flour mixture, then egg wash, and finally in bread crumbs.
Heat about 1-inch shortening in a skillet, over medium heat. Fry in batches, turning once, to brown on both sides (about 1 1/2 minutes on each side). Drain on a plate lined with paper towels. Serve immediately with chipotle dipping sauce.
CHIPOTLE DIPPING SAUCE: In a small bowl whisk together mayonnaise, chipotle pepper and lime juice, until well combined. Cover and refrigerate until ready to serve.