Preheat the oven to 350°. In a small bowl, mix the oil, garlic, lemon zest, turmeric, crushed red pepper, and 1 tsp. salt. Place the cauliflower, stem-side up, in an ovenproof skillet. Pour half of the oil mixture evenly over the cauliflower. Turn the cauliflower over and pour the remaining oil mixture over the top. Arrange the lemon slices around the cauliflower. Pour the stock into the skillet. Roast until the cauliflower is tender, basting often with a large spoon, about 1 hour and 15 minutes.
In a large bowl, mix the rice, apricots, and pistachios; season with salt and pepper. Arrange the mixture on a platter. Top with the cauliflower, lemon slices, and mint.