Remove Wagyu beef and foie gras from refrigerator 15 minutes before cooking and remove from packaging.
Season the filets mignons and foie gras slices with salt and pepper; set aside.
In a large skiller over medium heat, add the vegetable oil and saute the filets mignons over medium high heat for 3 minutes one side, turn and saute the other side for 2 minutes for medium rare to medium. Remove the filets from the skillet, set aside and keep warm.
Discard all fat from skillet. While the skillet is still hot, add the port wine, scraping the bottom of the pan. Reduce by half.
Add the veal stock, bring to a boil, then remove from heat and stir in the truffle butter to make a silky sauce.
While sauce is reducing, heat another small skillet to medium high heat. Place foie gras slices in skillet and saute for one minute.
Turn and saute for 30 seconds. Place on paper towels. Discard fat.
Place the filet on a warmed plate, place a foie gras slice on top of the filet. Spoon the sauce over the top.