Make the cauliflower rice: Remove the stem and outer green leaves. For a food processor, roughly chop the cauliflower into smaller pieces. Pulse the cauliflower florets using the grater attachment for the best results. If not, you can process it in the normal way. Add the cauliflower florets to the food processor and pulse into small rice-like pieces, working in batches if necessary. Box grater: Cut into four quarters. Carefully grate the cauliflower quarters against the medium-sized holes of the box grater. Repeat until the whole cauliflower is in small rice-like pieces.