Rinse and pat dry the head of cauliflower and strip away its green outer leaves.
Cut cauliflower into sections; individual florets if using a food processor or high-speed blender, larger chunks if using a box grater or chopping by hand. If chopping by hand, remove most of the stem.
Dice cauliflower sections using method of choice to create even-sized rice-like granules.
To cook cauliflower rice in the microwave:
Place 1 serving of cauliflower rice in a bowl and cover with plastic wrap or a plate. Microwave on High until heated through, about 3 minutes.
On the stovetop:
Stir-fry cauli-rice over medium-high heat, with oil and salt if desired.
In the oven:
Preheat oven to 400 degrees F (200 degrees C).
Toss cauliflower rice with olive oil and salt and spread it into a single layer on a baking sheet, then roast until "rice" is dry, stirring halfway, about 12 minutes.
Notes
Freeze raw cauliflower rice for up to 3 months in resealable zip-top bag. To defrost, microwave on low in a heat-proof bowl.