Wash the fish and pat dry.
Cut the fish into bite size pieces.
Beat the egg whites with a mixer until stiff.
Mix in 1/2 cup tapioca starch, the cassava flour, salt and pepper.
Heat the lard in a deep fryer or frying pan. Wait till it comes up to temperature.
Dredge the cut fish pieces in the remaining tapioca starch. Then dip in the batter mixture. Spread batter over the fish.
Place in the fish pieces in the deep fryer. Cook for about 3 minutes then flip the fish. Cook for another 3-4 minutes until golden brown. Make sure the fish is cooked all the way through.
Remove the fish from the deep fryer and let them cool on a paper towel.