I like to make these tacos by starting off with a light layer of cabbage on the bottom, then the sauce, a few chunks of fish, the scallions, a couple of slices of banana pepper and a squeeze of lime. Once the fish is finished off, you can do what I do, and make cabbage tacos—everything except the fish! So good!
For the Fish:
In a bowl, combine the oil, spices, salt and pepper. Add the fish and make sure each piece is coated with the marinade.
For the Cumin Mayo:
In a food processor, add the mayonnaise, garlic, mint, cumin, lime zest and lime juice. Whizz until smooth. Season with the salt, pepper and more lime juice, if necessary. Pour into a bowl and set aside.
Heat a large, nonstick saute pan over medium heat. There's no need to add oil since the fish is already coated in oil. Once the pan is warm (test it by sprinkling some water into the pan— if it sizzles and evaporates, you're ready), place each piece of fish in the pan. The fish should sizzle gently but firmly when it hits the pan. Cook until cooked through, but still moist, about 3 minutes per side. The fish should flake easily with a fork. Don't overcook your fish and it will taste awful!
Remove the fish from the pan and serve immediately with the warmed tortillas, cabbage, cumin mayo, scallions, slices of banana pepper (if desired) and a squeeze of lime.