Preheat the oven to 200°C.
Drizzle oil over sweet potato wedges in a roasting tin and bake for 25 to 30 minutes until golden.
Prepare three plates with flour, beaten eggs, and a mixture of breadcrumbs, cayenne pepper, and lemon zest.
Season fish strips and coat each piece in flour, then egg, and finally the breadcrumb mixture.
Fry fish in hot oil for 2 to 3 minutes per side until golden and drain on kitchen paper.
Boil peas for 3 to 4 minutes until tender, then drain and crush with a masher.
Stir crème fraîche and mint into the crushed peas and season to taste.
Mix lemon juice into mayonnaise and season with salt and pepper.
Serve goujons with a dollop of lemon mayonnaise, sweet potato wedges, and mushy peas.