Savory Scones with Gruyere, Prosciutto and Green Onion

In a large bowl, whisk together the flour, sugar, baking powder and salt. Using a pastry cutter, cut the butter into the flour mixture, until you have course crumbs. This can also be done with two knives or a food processor.
Whisk the eggs lightly and combine with the buttermilk. Add to the flour mixture and stir until just moist.
In a small bowl, mix together the gruyere, prosciutto, parmesan and green onion. Add this to the batter, then mix lightly. The dough will be sticky.
On a lightly floured surface, turn the sticky dough out and knead lightly until all the cheese, prosciutto and green onion are incorporated into the dough. Roll the dough 3/4 inch thick. Cut out 3 inch squares, then cut diagonally to make triangles. You should have about 10 scones. Place the scones on a baking sheet lined with parchment or a silicone mat, and lightly brush with half and half. Sprinkle with sea salt.
Place the scones in the freezer for 30 minutes. Meanwhile, preheat the oven to 400 degrees F.
Once the scones are chilled, bake for 20 minutes, or until golden. Sprinkle with additional parmesan cheese and serve warm.