Tiella barese

Step 1: Sort the 2 ⅝ lb live mussels: tap any open ones on the worktop and throw away those that stay open, and any with broken shells. Keep them cold in the fridge until you use them.

Step 2: Open the mussels raw: slide a small knife between the shells, cut the muscle and pull off the empty top shell. Do this over a bowl to catch the juice, then strain the juice through a fine sieve. If they're hard to open, steam them in a covered pan over a high heat for 2 minutes just until they gape, and throw away any that stay shut.

Step 3: Heat the oven to 400°F (350°F fan). Oil a deep 28 cm baking dish with 1 ¾ tbsp olive oil and spread 1 onion over the base.

Step 4: Add half of 12 ½ oz waxy potatoes in an overlapping layer, then half the 5 ½ oz cherry tomatoes, half the 1 garlic cloves, 2 tbsp flat-leaf parsley and 1 ⅜ oz pecorino. Season with some of ½ tsp salt and ¼ tsp black pepper.

Step 5: Arrange the mussels on the half shell over the top, meat side up, then scatter over 10 ½ oz arborio or carnaroli rice so it falls into the shells and gaps.

Step 6: Cover with the rest of 5 ½ oz cherry tomatoes, 1 garlic cloves, 2 tbsp flat-leaf parsley, 1 ⅜ oz pecorino, ½ tsp salt and ¼ tsp black pepper, and finish with the remaining 12 ½ oz waxy potatoes in a neat layer.

Step 7: Pour the strained mussel juice and 2 ½ cups water gently down the side of the dish until the liquid just reaches the top potato layer. Drizzle with the rest of 4 ¼ tbsp olive oil. Too little water is the most common mistake: the rice stays chalky and the potatoes hard.

Step 8: Bake until the rice is tender, the potatoes on top are golden and the liquid has been absorbed. Check after 40 minutes and add a little boiling water if it looks dry.

Step 9: Rest for 10 minutes before serving.