Preheat oven to 425°F.
Rice the cauliflower using a food processor (pulse gently; do not run continuously to avoid making mush) or a box grater (use the medium-sized holes).
Gently press the riced cauliflower with a paper towel to remove any lingering moisture before cooking.
Toss the riced cauliflower with a drizzle of olive oil or avocado oil.
Spread it in a single layer on a baking sheet.
Roast for 10 to 15 minutes, stirring once during cooking if making a large batch. The cauliflower rice is done when it is lightly golden and crisp.