Whisk together the flour, sugar, baking powder, garlic powder, salt, and black pepper in a large bowl.

Stir in the chopped chives and shredded cheese.

Grate the frozen butter into the flour mixture and combine gently until you achieve pea-sized crumbs.

Whisk together the cold buttermilk and egg yolk, then pour over the dry ingredients along with the chopped chicken ham and mix until clumped together.

Shape the dough into a ball, press down into an eight-inch disc, and cut into eight wedges.

Brush the scones with the egg wash mixture and sprinkle with flaky sea salt if desired.

Refrigerate the shaped scones for at least fifteen minutes.

Preheat your oven to 400°F (204°C).

Arrange the scones on a baking sheet and bake for about twenty-two to twenty-five minutes until golden brown.

Let the scones cool on the sheet for a few minutes before transferring them to a wire rack.