Pour the vegetable oil into a medium-sized deep saucepan and begin to heat ready to fry the goujons.
Meanwhile, place the cod pieces in a bowl, add the flour and paprika and season with pepper. Toss well to lightly coat the fish. Place the beaten eggs in one bowl and the breadcrumbs, parsley and lemon rind in another. Toss the fish pieces in the egg, then in the lemon and herb breadcrumbs, pressing firmly to coat.
Test the oil to see if it is hot enough – lower a small piece of bread into the oil and if it turns brown in 20 seconds the oil is ready. Carefully lower the fish pieces into the hot oil and cook for 3–4 minutes until golden and cooked through. Remove from the oil using a slotted spoon and drain on kitchen paper.
To make the tartare sauce, mix the mayonnaise with the crème fraîche and mustard, then fold in the chopped gherkin and parsley.
Serve the goujons with the sauce to dip and peas, if liked.