Season the tenderloin cubes with salt and pepper to taste and set aside at room temperature as you continue preparing the recipe.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Stir in the shiitake mushrooms, and cook until they have wilted and are beginning to turn golden brown, about 5 minutes. Remove the mushrooms from the skillet and set aside; heat the remaining olive oil in the skillet until it begins to smoke, the sprinkle in the cubed beef tenderloin. Cook on all sides until browned on the outside and the meat is cooked just under your desired degree of doneness, about 5 minutes for medium rare. Remove the steak from the skillet and set aside.
Pour the port wine into the skillet and bring to a boil over high heat. Boil until the port has reduced by half, then whisk in the raspberry jam, Worcestershire sauce, beef broth, and shiitake mushrooms. Continue cooking until the sauce has reduced to 1/2 cup, about 30 minutes. Once reduced, stir in the tenderloin cubes, and reheat.
