Filet of Beef with Mushrooms and Blue Cheese

Name: Filet of Beef with Mushrooms and Blue Cheese
Ingredients: 2 1/2 pounds beef tenderloin, trimmed and tied; 7 tablespoons unsalted butter, at room temperature, divided; Kosher salt and freshly ground black pepper; 3/4 cup chopped shallots (3 large); 14 ounces mushrooms, such as cremini and/or shiitakes, stems discarded and caps sliced 1/4 inch thick; 1/2 cup ruby Port wine, such as Sandeman; 3/4 cup crème fraîche; 3 ounces Roquefort or other strong blue cheese, crumbled; 1 tablespoon minced fresh parsley