3 3/4 cups unbleached all-purpose flour
1 1/2 cups Masa Harina�
2 tablespoons plus 1 teaspoon baking powder
1 teaspoon salt
1/2 cup (1 stick) unsalted butter, well chilled
1/2 cup vegetable shortening, well chilled
2 cups buttermilk, chilled
Procedures : Position racks in the upper and middle thirds of the oven, and preheat oven to 450 degrees F.
Cut butter and shortening into small pieces.
In a large bowl, stir together 3 1/2 cups of the flour and all the masa, baking powder and salt. With a pastry blender, blend in the butter and shortening until the mixture resembles a coarse and slightly lumpy meal. Stir in buttermilk until a soft, crumbly dough is formed. Sprinkle work surface with half the remaining flour. Turn the dough out, gather it into a ball, and briefly knead it, just until it holds together. Flatten the dough, sprinkle it with the remaining flour, and roll it out until it is about 1 inch thick. Form the biscuits with a 3-inch round cutter, and transfer them to two ungreased baking sheets, spacing the biscuits about 2 inches apart. Gather the scraps into a ball, roll it out to a 1-inch thickness, and cut out remaining biscuits.
Set baking sheets on the racks, and bake for about 15 minutes, or until they are golden and crisp. At the halfway point, exchange the position of the sheets on the racks from top to bottom and from front to back.
Serve the biscuits hot or warm