Carefully, and away from the heat, stir in 1/2 cup brandy.
Place the pan over medium-low heat and add chicken stock, beef granules (or 1 beef cube), thyme, black pepper. (If adding in pan drippings, *see note.) Bring mixture to a low boil, reduce heat to low and cook 8-10 minutes or until liquid is reduced by half.
Stir in the heavy cream. Keep mixture at a gentle boil, stirring occasionally, about 10-15 minutes or until the sauce is reduced to a little thicker than heavy cream.
Remove the mixture from the heat and whisk in grated Parmesan cheese.
Once cheese has melted, season to taste.
Brandy Peppercorn Sauce can be made up to three days ahead. When ready to use, reheat the sauce slowly in a small saucepan over low heat.
The sauce can be made with or without pan drippings – also the pan-drippings can be added even if the sauce is made ahead. After the beef is cooked, deglaze the pan with ¼ cup brandy and cook until reduced by half. Add the deglazed drippings to the already prepared sauce. Bring the sauce to a low boil and cook 3-5 minutes or until the sauce has thickened again.
***Keep leftover sauce refrigerated and in an air-tight container.