Using a small processor or coffee grinder process the nuts until they are ground fine and spread them out evenly on a large plate
Whisk the egg in a shallow soup bowl and mix in the salt and pepper (and any other seasonings you may like)
Dip the fillets in the whisked egg, being sure to cover the entire piece on both sides
Dredge the fillets in the crushed pecans until thoroughly coated
Heat the tallow in a large frying pan
Place the fillets in the pan and fry on medium heat on each side until browned and cooked through (approximately 5 - 6 minutes each side, depending upon the thickness)