Preheat the oven to 425°F. Lightly grease a baking sheet, or line it with parchment.
Mix together the flour, salt, baking powder, and sugar. Work the butter (using a pastry blender or fork) into the flour until the mixture is unevenly crumbly, with some of the butter remaining in larger pieces.
Mix in the cheese, chives, and bacon until evenly distributed.
Add 200g of the cream, stirring to combine. Try squeezing the dough together; if it’s crumbly and won’t hang together, or if there are crumbs remaining in the bottom of the bowl, add cream until the dough comes together. Transfer the shaggy dough to a well-floured work surface.
Shape the dough into a smooth 7" disk about ¾" thick. Transfer the disk to the prepared baking sheet. Use a knife or bench knife to cut the disk into 8 wedges, spreading the wedges apart a bit on the pan.
Brush the scones with egg wash
Bake the scones for 20 minutes at 425°F, lower down the temperature to 405°F and bake for another 15 minutes, until they’re golden brown. Remove from the oven, and cool right on the pan. Serve warm, or at room temperature.