Clean cauliflower in advance and let air dry. Heat oven to 400 degrees F (200 degrees C). Remove the outer leaves from the cauliflower, cut it into quarters and remove most of the thick core. Cut each quarter into four or five chunks. Add a piece at a time to blender and pulse until cauliflower is the size of rice or couscous, removing pulsed pieces before adding more. Don’t overload blender. Toss with olive oil and spread onto baking dish. Do not season until after cooked! Roast rice for 12 minutes, mixing it in the tray halfway through cooking. Don’t walk away from this as it burns quickly. Add salt to finished cauliflower rice (you can add other seasonings, butter or sauces as you like). Use as rice replacement in your favourite dishes. Store in the fridge for up to three days, or in the freezer for two months.