Preheat oven to 375°F (190°C). In a bowl, toss the lamb cubes with olive oil, cumin, coriander, turmeric, cayenne pepper (if using), salt, and pepper. Mix well to ensure the lamb is evenly coated with the spices.

Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Sear the lamb cubes in batches until browned on all sides. This step adds flavor and texture to the meat. Remove lamb from skillet and place in a single layer on a baking sheet.

Place the baking sheet with the lamb in the preheated oven and roast for 30 minutes, or until the lamb is cooked through. Use a meat thermometer to ensure the internal temperature reaches at least 145°F (63°C) for medium-rare or 160°F (71°C) for medium.

While the lamb is roasting, steam the cauliflower florets until tender, about 15-20 minutes. You can also boil them if you prefer. Ensure they are soft enough to purée easily.

In a food processor or blender, combine the steamed cauliflower, olive oil, vegetable broth, minced garlic, salt, and pepper. Purée until smooth and creamy, adding more vegetable broth if needed to reach the desired consistency.

Spoon the cauliflower purée onto plates. Top with the roasted lamb cubes. Garnish with fresh parsley and toasted pine nuts (optional). Serve immediately.