Rinse cauliflower under cool water and pat dry. Using a cheese grater, grate the cauliflower to a coarse texture (approximately the size of rice grains). Using a food processor to pulse the cauliflower to desired texture works as well. Heat the coconut oil in a skillet over medium heat. Sauté the onion and garlic for 3–4 minutes, or until the onion is relatively translucent. Add in the cauliflower rice and continue to sauté for 4–5 minutes. Season with salt and pepper, and serve.