For the cod cheeks, blend the bread to crumbs in a food processor, then add the lemon zest and pulse again to combine. Tip the mixture into a shallow bowl and clean the food processor.
Sprinkle the flour onto a plate and season with salt and freshly ground black pepper. Beat the eggs in a bowl.
In batches, dust the cod cheeks in the flour, then dip them in the beaten egg, then roll them in the breadcrumb mixture until completely coated. Place each breaded cod cheek on a plate. Cover with cling film and chill in the fridge until needed.
For the salsa, blend the peas, mint, chillies, lime juice and crème fraîche in the food processor to a rough paste. Tip it into a serving bowl, cover and chill until needed.
Heat the oil (and dripping, if using) in a deep-fat fryer to 190C. Alternatively, heat the oil in a deep, heavy-based saucepan until a breadcrumb sizzles and turns golden-brown when dropped into it. (CAUTION: Hot oil can be dangerous. Do not leave unattended.)
Carefully lower the cod cheeks into the hot fat in batches, and fry for 2-3 minutes, or until golden-brown and cooked through. Remove from the oil using a slotted spoon and set aside to drain on kitchen paper. Repeat the process with the remaining cod cheeks.
To serve, pile the breaded cod cheeks onto a serving platter. Place the lemon wedges and the bowl of pea salsa alongside.