Put a 9 or 10-inch cast iron skillet on the stove, and heat over medium-high heat. Generously coat with avocado oil.
Pour the cauliflower into the pan, and use a metal flat-bottomed measuring cup to press into the pan, forming a high, thick crust around the edges of the pan.
Allow the crust to begin cooking on the stove top for about 8 minutes. While the crust is browning, I use a silicone spatula to gently separate the edge of the crust from the sides of the pan, so the crust stands about 1/2 inch inside the pan on it's own. This will help is come out of the pan in neater slices after it's baked.
Add the cast iron skillet to the oven, and continue to bake the crust for 20-25 minutes, until the crust has browned and firmed. If you like your crusts to have a crunch to them, allow the crust to brown a few extra minutes.
Remove the crust from the oven (but leave the oven on!), and top your pizza. Add sauce, cheese, and any toppings you desire.
Return the skillet to the oven and bake for an additional 10-14 minutes, until the cheese is melted and bubbly.
Cut into slices, and gently loosen the slices from the edge and bottom of the pan. The first slice is a bit tricky to remove, but the others come out pretty cleanly.