Cut the chorizo into pieces and process in a food processor until it is finely chopped. Alternatively, chop it finely with a knife. Add the breadcrumbs, tomato paste and 1 tablespoon of the oil and blend until combined.
Lay the plaice fillets, skinned-side up, on the work surface. Spread each with a thin layer of the chorizo mixture and roll up, starting from the thick end.
Put the fish in a large, shallow, ovenproof dish and tuck the tomatoes and thyme around the fish. Drizzle with the remaining oil and the wine and season the fish lightly with salt and pepper.
Bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 20–25 minutes, or until cooked through.