Prepare the peppercorns: Place the peppercorns in a resealable plastic bag and use a rolling pin or the bottom of a heavy pan to crush them. You want a coarse grind, not a fine powder.
Sauté the aromatics: Melt 2 tablespoons of butter in a skillet over medium heat. Add the finely chopped shallots and cook for 3–4 minutes, or until soft and translucent.
Deglaze the pan: Remove the pan from the heat. Carefully pour in the whisky. Return the pan to medium-high heat and allow the alcohol to burn off and the whisky to reduce by half, about 1–2 minutes.
Add liquid and thicken: Stir in the beef stock, crushed peppercorns, and Worcestershire sauce. Bring the mixture to a simmer and let it reduce for about 5 minutes, allowing the sauce to thicken slightly.
Finish the sauce: Reduce the heat to low and whisk in the heavy cream. Simmer gently for 2–3 minutes, until the sauce reaches your desired thickness. Do not let it come to a full boil after adding the cream.
Enrich and season: Remove the pan from the heat and whisk in the remaining tablespoon of butter. Taste and season with salt if needed.
Serve: Pour the sauce generously over your grilled steak, pork chops, or chicken.