Roast Tenderloin of Beef with Porcini-Shallot-Tarragon Pan Sauce – It’s the Heat and the Humidity!

2 1/2 to 3 lb beef tenderloin roast

salt and pepper to taste

1 tbsp vegetable oil

2 tbsp unsalted butter, divided

1/2 cup sliced shallots

1/4 cup tarragon white wine vinegar, or plain white wine vinegar

1 cup veal stock or chicken broth

1/4 cup cream

1/3 cup dried porcini mushrooms, soaked and diced

1/2 cup liquid from porcini mushrooms, more if needed

1 tbsp minced fresh tarragon