Prepare all the ingredients. Crush the peppercorns in a mortar and pestle until coarsely cracked—this will give the sauce its texture.

Melt the butter with the oil in a pan over medium heat. Add the onion and cook until softened. Stir in the salt and the cracked pepper.

Mix well and let it brown lightly, allowing the pepper to release its aroma, about 3 minutes. Add the brandy and simmer over medium heat for 1 minute.

Add the beef broth, red wine, and Worcestershire sauce. Simmer over low heat for 5 to 10 minutes, until reduced by half. Finally, add the heavy cream, heat gently without boiling, and serve over cooked steak. Taste and adjust seasoning with more salt if needed. You can make this sauce up to two days ahead and reheat gently over low heat before serving.