• Preheat your oven to 375°F. Line large rimmed baking sheets with bleached parchment paper and set aside.

"Rice” the cauliflower. (See Recipe Notes)

• Rinse the cauliflower florets thoroughly, and pulse them in a food processor until they are the texture of short-grain cooked rice (or grate the florets as finely as possible on a box grater).
• Place the riced cauliflower in a large, microwave-safe bowl (or a medium, heavy-bottom lidded stockpot), add about 2 tablespoons water and cover tightly with plastic wrap (or the stockpot lid).
• Cook on high for 3 to 4 minutes (or over medium heat for about 5 minutes) until the cauliflower is more tender but still firm.
• Uncover the bowl or stockpot, and allow the cauliflower to cool until no longer hot to the touch.
• Transfer the cooked and riced cauliflower to a large tea towel, cheese cloth, or fine mesh bag, gather the towel, cloth or bag tightly around the cauliflower and wring out all the moisture. There will be more moisture than you expect.
• Keep wringing it out until the cauliflower is clumped and almost entirely dry. Set the cauliflower aside.

Make the tortilla mixture.

• Place the prepared, riced cauliflower in a large bowl, add the salt, pepper and Parmigiano-Reggiano cheese, and toss to combine. Add the beaten eggs and mix until well-combined.
• Add the (optional) tapioca starch/flour and mix again to combine. This is particularly useful if you think you may not have squeezed all the moisture out of your riced cauliflower.

Shape and bake the tortillas.

• Divide the mixture into 6 equal portions, and roll each into a loose ball with wet palms. Place about 6 inches apart from one another on the prepared baking sheets.
• With wet hands, pat the balls into rounds about 1/4-inch thick and 4 1/2-inches in diameter, making sure the parchment paper doesn’t show through the rounds at all.
• Place the baking sheets, one at a time, in the center of the preheated oven and bake for 12 minutes or until golden brown on the edges.
• Remove from the oven, and using a wide spatula, carefully flip the tortillas over. Return to the oven and bake for 5 minutes more, or until dry and firm to the touch.
• You can finish and/or rewarm the tortillas right before serving by browning the side that is relatively pale (the tops, before the tortillas were flipped) in a hot, dry cast iron or nonstick skillet. Serve warm.