1. Arrange lamb in one layer in a rimmed dish. Combine oil, rosemary and chilli in a small bowl, pour over the lamb and turn to coat. Refrigerate overnight.

2. Preheat barbecue to moderately high and oil the grate. Drain lamb and season all over with salt and pepper. Grill lamb for 20 minutes for medium-rare, turning once. Rest for 15 minutes, then cut between the bones. Arrange on a platter.

3. Boil potatoes in lightly salted water for about 25 minutes, or until tender. Drain and stand for 20 minutes, then cut in half.

4. While potatoes are cooking, make aioli. Place garlic and salt in a mortar and crush to a paste. Stir in mustard, lemon juice and both oils to combine well. Place mayonnaise in a bowl and gradually add oil mixture, whisking constantly until thickened. Season with salt and pepper. Set aside.

5. Toss potatoes with thyme and oil; season with salt and pepper. Transfer to platter with lamb and serve with aioli.

Recipe Loukie Werle
Photography William Meppem
Styling Kirsty Cassidy