Preheat your oven to 400°F (200°C). In a small bowl, mix minced garlic, chopped rosemary, olive oil, salt, and pepper. Rub this mixture over the lamb rack.

Roast the Lamb

Place the lamb in a roasting pan and roast for about 20-25 minutes for medium-rare, or until it reaches your desired doneness. Let it rest for 10 minutes before slicing.

Ulu Gratin Preparation

Prepare the Ulu

While the lamb is roasting, boil the cubed ulu in salted water until tender (about 15 minutes). Drain and mash slightly.

Make the Gratin

In a bowl, mix the mashed ulu with heavy cream, parmesan cheese, nutmeg, salt, and pepper. Pour into a baking dish and bake in the oven alongside the lamb for about 20 minutes or until golden on top.

Vegetable Preparation

Roast the Vegetables

Toss the asparagus and carrots with olive oil, salt, and pepper. Spread on a baking sheet and roast in the oven for 15-20 minutes until tender.

Truffle Vinaigrette Preparation

Make the Vinaigrette

In a small bowl, whisk together truffle oil, balsamic vinegar, Dijon mustard, honey, salt, and pepper until well combined.

Plating

Serve

Slice the lamb rack and serve it alongside the ulu gratin and seasonal vegetables. Drizzle the truffle vinaigrette over the vegetables before serving.