BUTTERMILK BISCUITS WITH PARMESAN AND ONION

2 3/4 cups all-purpose flour
1 tablespoon plus 1 1/2 teaspoons granulated sugar
1 tablespoon plus 1 teaspoon baking powder
2 teaspoons salt
1/4 teaspoon baking soda
10 tablespoons chilled unsalted butter, cut into small pieces
1/4 cup minced onion
1 tablespoon chopped fresh thyme or 2 teaspoons dried thyme
1 cup buttermilk
1 tablespoon milk or cream
1/4 cup grated Parmesan cheese

Combine flour, sugar, baking powder, salt and baking soda in a food processor fitted with the metal blade. Add butter, onion and thyme; process until the mixture resembles fine meal. Pour the buttermilk through the processor feed tube with the machine running; process just until the dough comes together.

Turn out the dough on a well-floured work surface; knead lightly into a round ball. Roll out dough to a 1-inch thickness; cut biscuits with a 2-inch cutter. Place biscuits on parchment-paper-lined baking sheets. Gather up remaining dough; knead lightly. Repeat, rolling out and cutting with remaining dough. Cover with plastic wrap; refrigerate at least 1 hour or up to 24 hours.

WHEN READY TO BAKE:
Preheat oven to 350 degrees F.

Uncover baking sheets; lightly brush biscuit tops with milk; sprinkle with Parmesan cheese.

Bake until light golden brown, about 25 minutes.

Makes 24 biscuits
Adapted from source: Live, Love, Eat! The Best of Wolfgang Puck