Cut the mahi mahi filets into strips and pad them dry with a paper towel.
Mix the breadcrumbs, Mexican seasoning, salt, and pepper in a bowl.
Crack the egg in a second bowl and whisk it to combine the yolk with the white.
Put the flour in a third bowl.
Cover the fillets with flour, then soak them in the egg mixture, and cover both sides with the breadcrumbs.
Heat the oil to 350°F (180ºC), then fry one or two at a time for 3-4 minutes on each side until they're golden brown.
Transfer to a plate lined with paper towels or a wire rack to drain excess oil.
Mix all the sauce ingredients in a bowl until combined and serve for dipping with the fried mahi mahi. Enjoy!
