Preheat the oven to full whack.

Rinse your clams under cold running water and pull off any seaweed. Make sure the shells are all tightly closed. Spread out in a roasting tray.

Slice the chillies and unpeeled garlic lengthways, then scatter over the clams. Pick over the rosemary leaves, then drizzle everything with olive oil and pop in the oven.

Roast for 5 to 6 minutes, or until the shells start to open.

Turn the tray around to make sure the clams cook evenly, then return to the oven until all the clams are open.

Remove them from the oven and squeeze over the juice from half a lemon. Using tongs, lift the clams onto a serving dish and spoon any tray juices over the top.

Drizzle with extra virgin olive oil and serve with crusty bread. Cut the remaining lemons into wedges and serve on the side for squeezing over.