Nick Butcher on Fiestas and Foods of Spain

This is a favourite Spanish Christmas dish of a whole fish roasted on a bed of potatoes and onions. Besugo is a sea bream, easily identifiable by its big eyes and large black spot behind the gills. It is very expensive at Christmas time, and there's no reason why you shouldn't use something else, such as dorada or urta. The fishmonger should gut and scale it, but never seems to do a very thorough job, so check for any scales he or she's left behind, and rinse out any traces of blood remaining in the stomach cavity or along the backbone. You will also need an oven dish just big enough to hold the fish.

1. Preheat your oven to about 200C. Mix the potatoes and onions together with two tablespoons of the oil and some seasoning. Place them in a non-stick frying pan and cook over a medium heat for about five minutes.
2. While they are cooking, season the fish with salt inside and out, then take a sharp knife and make several vertical cuts down one side of the fish. Halve one of the lemons lengthways, then slice one half across into half-moon shapes. Insert these slices into the cuts in the fish.
3. Brush the oven dish with a little oil and lay the onions and potatoes in an even layer in the bottom. Now put the fish, lemon side up, on top of them. Sprinkle the parsley and breadcrumbs over the fish and drizzle the remaining oil over.
4. Bake the fish in the oven for about 45 minutes, basting occasionally. If you're not sure whether it's done or not, use the 'press test'. Press a finger into the flesh of the fish. If it feels firm to the touch, it's cooked. If it feels a bit soft and yielding, it needs more time.
5. Remove the dish from the oven, and squeeze over the juice of the remaining lemons. Serve with the potatoes and onions from the dish, and a green vegetable if you wish.