Roast Lamb with Kumara and Mint Sauce

Preheat oven to 180°C. Pat the lamb dry, rub with one tablespoon olive oil, half the chopped rosemary, half the garlic, salt, and pepper, allowing it to marinate for 10 minutes.

Peel the kumara and cut into 2 cm cubes. Toss with the remaining olive oil, remaining rosemary, garlic, salt, and pepper, then spread evenly in a small roasting tray.

Heat an oven-safe skillet over high heat. Sear the lamb for 2 minutes per side until deeply golden brown, then transfer it on top of the kumara in the roasting tray.

Roast in the preheated oven for 40 to 45 minutes for medium doneness, or until a meat thermometer reads 60°C in the thickest part.

While roasting, prepare the mint sauce by finely chopping the mint leaves and combining them with the white vinegar and sugar in a small bowl; let it rest at room temperature for 10 minutes to develop flavour.

Prepare the gravy by melting butter in a small saucepan over medium heat, sautéing the chopped onion for 3 minutes until soft, sprinkling the flour and stirring for 1 minute, then gradually whisking in the stock and simmering for 4 minutes until thickened.

Remove the lamb from the oven, transfer to a warm plate, cover loosely with foil, and let rest for 8 minutes to retain its juices.

Slice the lamb against the grain, plate alongside the roasted kumara, spoon over the onion gravy, and serve with the fresh mint sauce on the side.