In a deep fryer or a large, heavy pot, heat oil to about 180°C (approximately 350°F). Oil is hot enough if bubbles form when the end of a wooden spoon handle is submerged in oil.
Rinse fish and pat dry. Season with salt and pepper and dredge in flour. Whisk eggs in a deep dish. Mix flour and nuts on a flat plate. Dip floured fish in egg and roll in nut mixture. Fry in batches in hot oil for about 5 minutes until golden brown. Keep cooked fish warm in oven.
To serve, arrange with orange segments on a plate, if desired.