Place the flour, baking powder, baking soda, pepper and salt into the bowl of a food processor. Pulse for a few seconds to combine the ingredients. Cut the butter into rough 1-inch chunks and add to the flour mixture. Pulse in 5-second bursts until the butter is reduced to pieces that are between the size of a green pea and an almond. Tip this mixture into a medium mixing bowl.

Pour the buttermilk over the flour mixture all at once and using a fork, stir gently to bring the mixture together. The dough will be shaggy with some dry patches. Turn the dough out onto a very lightly floured surface and pat into a vaguely rectangular shape with your hands. Fold the dough in half, pat it out and fold in half again. Now shape the dough into an approximately 6x6 square. Use a metal bench scraper to carefully transfer the dough onto a parchment-lined quarter sheet tray or other flat baking sheet.

Chill the dough square in the freezer for about 1 hour. Use the bench scraper or a sharp knife to cut the dough into squares or rectangles, whichever shape maximizes your yield. At this point, you could cover the entire tray with plastic wrap and freeze for up to 2 weeks before baking.

To bake, preheat the oven to 425° and position a rack in the center. Array the cut biscuits about ½ inch apart on the sheet tray, brush the tops with a lick of heavy cream and bake until pale golden brown on top, about 15 minutes. If baking from frozen, there is no need to thaw the biscuits. Simply proceed as above, perhaps adding a few minutes of extra baking time.

Pile the hot biscuits into a basket or on a platter and serve with smoked salmon (or ham) and eggs cooked to your liking.