1. Preheat oven to 400°F. Line a baking sheet with parchment paper and set aside.
2. Prepare the bacon, onion and cheese. Toss these ingredients together with 1 teaspoon flour; set aside.
3. In a medium sized bowl, combine the flour, baking powder, cayenne, nutmeg and salt. Cut in the butter with a pastry blender or two knives until the butter is pea-size. With a fork, lightly beat the eggs and half-and-half and add to the flour mixture. Add the bacon, onion and cheese mixture. Using a wooden spoon, fold mixture until it begins to come together.
4. Turn out the dough onto a well-floured surface and knead gently for less than one minute. Pat dough to ¾ to 1-inch thick and cut using 3-inch biscuit cutter (for large scones) or cut into squares or triangles. Place the scones on the prepared baking sheet. Brush the tops of the scones with the egg wash.
5. Bake for approximately 20 minutes, or until golden brown.