Preheat oven to 450°F (232°C).

Combine oats, flour, baking soda, and salt in a bowl and mix well.

Add butter and mix well using a food processor or pastry blender until the mixture resembles coarse crumbs.

Gradually add buttermilk or yogurt, mixing until a stiff dough forms (up to 1 1/3 cups may be needed).

Roll the dough to a thickness of 1/4 to 1/8 inch.

Cut out biscuits using a 2-inch biscuit cutter.

Place biscuits on a greased baking sheet.

Bake for 8 to 12 minutes, or until firm and lightly golden.

Optional: Serve with sliced white cheddar cheese or cinnamon sugar.