Preheat oven to 425 degrees F. Line a baking/cookie sheet with parchment paper.
Start by cutting your cauliflower in half. Measurements are based on using a large head of cauliflower. Cut the leaves and end of the cauliflower. Cut the cauliflower into small florets and toss into a food processor and process until the cauliflower reaches a rice/mashed potato look. It should be processed fine. The finer it is, the better the end result will hold together. Just be careful not to process down into mash, because you can create mashed cauliflower! It should have the look of rice/mashed potatoes.
Place the processed cauliflower into a microwave safe bowl and cook for 4-6 minutes, stopping to stir halfway through.
Once cooked, allow to cool for a few moments before handling. Add the remaining ingredients for the calzone portion and spoon the mixture onto the parchment paper, creating two flat pizza pies. Smooth out with the back of a spoon.
Place into the oven to bake for 12 minutes. Remove from the oven, slip a spatula under each one to loosen it from the paper and add the filling (or your filling of choice) to one side of each pie and fold one half over the filling.
Bake for an additional 8-10 minutes. Enjoy!
Serve with your favorite sides or pizza sauce!