1 1/2 cups (210 g) all purpose gluten free flour blend (I used Better Batter)
3/4 teaspoon xanthan gum (omit if your blend already contains it)
3/4 cup (100 g) coarsely ground yellow cornmeal
2 teaspoons baking powder
1 teaspoon kosher salt
6 tablespoons (84 g) unsalted butter, chilled
1/2 cup (113 g) plain yogurt, chilled
1/2 cup (4 fluid ounces) milk, chilled
Preheat your oven to 400°F. Line a rimmed baking sheet with parchment paper and set it aside.
Place the flour, xanthan gum, cornmeal, baking powder and salt in a large bowl, and whisk to combine well. Cut the 6 tablespoons cold butter into a large dice (see photo), and dump all the butter into the large bowl of dry ingredients (see photo). Toss the diced butter in the dry ingredients to coat (see photo), but not to break up the butter. Flatten each piece of diced butter in between your fingertips (see photo) without crumbling the butter.
Add the yogurt and milk to the bowl, and mix to combine, still taking care not to crumble the butter. The mixture should come together. It will not be very wet, so be sure to wet all the dry ingredients with the milk and yogurt.
Turn the dough out onto a large piece of plastic wrap. Press the dough into a flat disk and cover it tightly with the plastic wrap. Place the dough in the freezer for about 15 minutes, or until firm.
Once the dough is firm, transfer it to a piece of parchment paper, and press back into a flat disk if it has crumbled at all. Place another piece of parchment paper on top of the dough, and begin to roll into a rectangle about 1/4 inch thick. You should see flattened pieces of diced butter pretty clearly in the dough. Fold one short end of the dough over 1/3 of the rectangle, and then fold the other end on top. You will have folded the dough in thirds, like a business letter. The dough will likely crack a bit as you fold it. Turn the dough either clockwise or counterclockwise 1/4 of the way around (a 90° turn). Roll the dough out again into a rectangle about 1/4 inch thick. You have just completed one full “turn.”
Repeat the whole process for 2 or 3 more “turns.” By the second time you fold the dough like a business letter, it will be much smoother and won’t crack. After the final turn, roll into a rectangle about 8 inches wide by 16 inches long. Fold the dough in half so that it is an 8-inch square. It will be about 1/2 to 3/4 inch thick. Using a sharp knife or bench scraper, divide the dough into sixteen 2-inch squares.
Place the squares of biscuit dough about 1 inch apart on the prepared baking sheet. Place the baking sheet in the freezer and freeze until firm, about 15 minutes.
Remove the biscuits from the freezer and place them in the center of the preheated oven and bake for 15 to 20 minutes, or until golden brown and puffy, rotating once during baking.