Step 1

Preheat the oven to 425ºF, and line a baking sheet with parchment paper.

Step 2

Whisk together the flour, baking powder, salt, and herbes de Provence in a large mixing bowl. Add the cubed butter, and cut in with a pastry blender until it resembles coarse cornmeal and there are no pieces of butter larger than a pea.

Step 3

Whisk together the buttermilk and egg in a small bowl, and pour over the butter-flour mixture. Gently fold in until just absorbed; fold in the feta until it resembles a shaggy dough.

Step 4

Turn the dough out onto a lightly floured surface, and knead 6-8 times, or just until cohesive. Pat out into a rough rectangle, about 1/2-inch thick. Cut into 8 equal rectangles for large biscuits, or 16 triangles for smaller ones.

Step 5

Brush with egg wash (the water-egg mixture), and bake for 17-20 minutes, or until the tops are lightly golden.

Step 6

Cool slightly on a cooling rack.