Carpe à la Boulangère

• 1 carp, about 800 g/1¾ lb, or 2 smaller fish

Preheat the oven to 180°C/350°F/gas 4. Gut and scale the carp and rinse under cold water. Cut 3 deep slashes in each side of the fish and insert the bay leaves into the slashes on one side. Place the thyme into the cavity and set aside. Mix the potatoes and onions in a bowl. Season wit