2 tablespoons chopped walnuts
2 tablespoons chopped parsley
2 teaspoons dried oregano, divided
2 pound beef tenderloin
Salt and pepper to taste
2/3 to 3/4 cup beef broth
Preheat oven to 425° F.
Combine the blue cheese, walnuts, parsley and 1 teaspoon of oregano in a bowl and mix well. Cut a long pocket in the top of the tenderloin, starting and ending 1/2 inch from the ends, cutting to within 1 inch of the bottom. Spoon the cheese mixture into the pocket. Press the sides of the meat together and secure with string. Rub the remaining teaspoon of oregano, salt and pepper on the tenderloin.
Roast until an instant-read thermometer inserted in the thickest part of the meat reads 120° F. for rare, 125° F. for medium-rare or 135 to 145° F. for medium, about 25 to 45 minutes (the temperature will continue to rise 5 to 10 degrees out of the oven). Let stand for 5 minutes.
Remove to a platter and cover loosely with aluminum foil. Place the roasting pan over medium-high heat and add the beef broth. Cook until heated through, stirring to deglaze the pan. Pour into a sauceboat. Slice the tenderloin and serve with the pan juices.