Preheat the oven to 350°F (175°C). Line 2 baking pans with parchment paper.

In a large bowl, combine gluten-free cornstarch, rice flour, gram flour, and Parmesan cheese.

Rub the butter into the flour mixture with your fingertips until it resembles a dough.

Add the milk and finely chopped rosemary leaves.

Knead gently until the dough comes together.

Roll level tablespoons of the mixture into balls.

Place the balls 1 inch apart on the prepared baking pans.

Flatten each ball with the palm of your hand.

Using a fork, mark the top of each cookie in a crisscross pattern.

Bake for 15 minutes, or until lightly browned.

Cool in pans for 5 minutes.

Remove from pans and cool completely on a wire rack.