Defrost your fish filets in a bowl of cold water for 20-30 minutes or overnight in the refrigerator.
In a small bowl, combine the chili powder, brown sugar, salt, and garlic powder. Zest the lime into this mixture and stir to combine.
Remove the tilapia fillets from the package and pat dry with a paper towel. Sprinkle the spice mixture evenly over each fish filet on each side, and rub it into the fish to coat.
Heat the oil in a nonstick skillet over medium-high heat. Once the oil is glistening, add the seasoned tilapia in an even layer, being sure to not crowd the pan. Cook for 4 minutes undisturbed and then carefully flip the fish over.
Squeeze the juice of the zested lime over the fish while in the pan, and finish cooking the fish for 2-3 minutes or cooked through and opaque and flaky.
Remove the tilapia from the skillet and let rest for 5 minutes. Serve with or without the salsa.
Apple Salsa
Mix together apple, cilantro, and red onion with the zest and juice of a lime. Season with salt and mix well. Serve with the fish as desired.
Notes
Note on Pan-Frying Tilapia: Do not overcrowd your skillet, as this will cause your tilapia to steam and not brown. Instead, you can use half the oil and cook in 2 batches if needed.Oil: Use olive oil to pan-fry tilapia, or another high-smoking oil such as coconut, peanut, or vegetable oil.Apple Salsa: This is completely optional, but if using it, using a granny smith apple is key to this tart and bright salsa. I would not use a sweeter apple. If you don't have granny smith apples, pineapple would be a great substitution.Leftovers: Fish is best served fresh, but leftovers will keep for 2 days in the refrigerator.