Add the cauliflower florets to a food processor fitted with the blade attachment, and pulse 10-15 times, until the florets are roughly the consistency of rice. Some chunks are OK, just pick them out before you cook. If you don't have a food processor, you can grate the florets on a box grater or mince them by hand.

Combine all ingredients for the marinade in a small airtight container or ziploc bag, and shake or stir everything together to combine. Add the skirt steak and shake or stir to coat the steak with the marinade. Refrigerate and marinate for a minimum of 6 and a maximum of 24 hours, flipping halfway through.