Pour the brandy or cognac into the same skillet, allowing it to simmer vigorously while scraping the browned bits from the bottom of the pan. Continue until the liquid has reduced, and the strong alcohol aroma is gone, about 1 minute. Add the beef broth and simmer rapidly for 2–3 minutes until reduced by half. Reduce the heat to medium, stir in the heavy cream and crushed peppercorns, and let the mixture simmer gently for 1½–2 minutes, thickening slightly. Avoid rapid boiling. Taste the sauce and adjust with additional salt or pepper if needed.