Prep: 50 mins | Bake: 20 mins | Yield: 8 biscuits
2 cups all-purpose flour, plus more for kneading
1 tablespoon baking powder
¼ teaspoon salt
1 ½ sticks cold unsalted butter, diced
½ cup cold buttermilk
1 cold extra-large egg
1 ¼ cups grated sharp cheddar cheese
2 tablespoons chopped fresh chives
1 egg, beaten with 1 tablespoon milk
Combine 2 cups flour, baking powder and salt in the bowl. Add the butter and mix until well incorporated. Combine the buttermilk and egg in a small measuring cup and beat lightly. With the mixer on low, quickly add the buttermilk mixture to the flour mixture and mix only until moistened. Fold in the cheddar cheese and chives, if using add mix until roughly combined.
Dump out onto a well-floured flat surface and knead lightly about 6 times. Roll the dough out to a rectangle 10 x 5-inch. With a sharp floured knife, cut the dough into half lengthwise, and then across, making 8 rectangle biscuits. Transfer to a baking sheet pan lined with aluminum foil or parchment paper. Brush the tops with the egg wash and bake for 20 minutes (center rack). Serve hot or warm.
Note: You can cut the dough to a smaller size to make 10 to 12 biscuits, if you wish but be sure to bake them 5 to 8 minutes less than the original cooking time. Otherwise they would come out dry and chewy.