Rinse catfish fillets and pat dry with a paper towel. If you prefer to have smaller pieces, you can cut the catfish into strips. Season generously with sea salt and ground black pepper. Let sit for 10-15 minutes, flipping and seasoning the other side after 5-8 minutes.
Combine cornmeal, chickpea flour, garlic powder and cayenne pepper in another shallow dish.
In a large skillet, add oil over almost-high heat. You will know when the oil is ready when a very, very small amount of water tossed into the pan sizzles and dances.
Using a fork, tongs or your hands, take one fillet transfer fillet to the cornmeal mixture and coat thoroughly. Shake off excess cornmeal mixture and carefully place fish into the hot pan. Saute until golden brown, about 3-6 minutes per side, depending on the size of fillet or strip. Careful not to crowd the fish in the pan. Once golden-brown on each side, carefully remove and place on a plate lined with paper towels and drain. Take care to handle the fish tenderly, as the fish will be very tender and may try to fall apart and/or separate from the fried cornmeal coating. I found it best to use a slotted spatula at this point to keep the fish from tearing. Season with salt or pepper as needed.