1 Heat the oil to 170°C (approximately 340°F) in a fryer or large pot. (The oil is hot enough when bubbles appear around the handle of a wooden spoon that has been immersed in the oil.)
2 Peel the potatoes and cut in sticks as for french fries. Add them to the oil in batches and fry about 5 minutes until they are soft but not brown. Remove and drain. Increase the temperature to 190°C (approximately 375°F) and fry the potatoes again in batches for about 2 minutes until crispy. Remove, drain well and sprinkle with salt.
3 Rinse the fish fillets and pat dry. Season with salt and pepper and sprinkle with lemon juice. Beat the eggs in a wide shallow bowl or pie pan. Put the flour on a plate and place the breadcrumbs on another plate. Coat the fish with flour, dip in eggs, and then coat in the breadcrumbs. Fry the fish fillets one at a time at 170°C (approximately 340°F) in a fryer (or pot) until golden brown, about 4–5 minutes. Serve fried potatoes with the fish.