Mince the shallots.
Heat your saucepan over medium-high heat, add the oil and let it get hot but not smoking. Add the shallots and cook until they are a golden brown but pay attention and keep stirring so they don't burn and you have to start all over again. Should take about 4 to 5 minutes.
Add the mustard and sherry vinegar. By the way, sherry vinegar is not that easy to find. If you can't find it in your local supermarket, you may have to look in a fancy gourmet store like William Sonoma or try finding it on the Internet.
Reduce this combination by half, which takes only about 1 minute.
Add the brandy or Cognac and cook to burn off all the alcohol. About 3 minutes. I like to remove the pan from the flame on the stove top before adding any liquid that contains alcohol and can potentially blow up in my face. It shouldn't happen if you remove the pan, but be careful.
Add the red wine and port and reduce again by half. This takes a good 20 minutes. You want the sauce to be simmering so if starts to boil, reduce the heat to medium or medium-low.
When the sauce is reduced, remove it from the heat and add the cream, butter and crushed peppercorns. Taste and season for salt.