6 tablespoons olive oil, plus extra for oiling and drizzling
75 g (3 oz) dried breadcrumbs
salt and pepper
Mix together the butter, garlic, Parmesan and parsley in a small bowl.
Cut the cod into pieces about 2.5 cm (1 inch) thick, then season. Use a small, sharp knife to make a little pocket in the centre of each piece of fish. Push a small spoonful of butter inside each pocket. Close up the pockets so that no butter is visible.
Place the oil and breadcrumbs on separate plates. Dip each piece of fish in the oil until really well coated, then roll in the breadcrumbs to coat. Place on an oiled baking sheet and drizzle over more oil. Place in a preheated oven, 200°C (400°F), Gas Mark 6, for 15 minutes until golden, crisp and cooked through.