Beef Tenderloin with Marsala without bourbon stuffing mayonnaise

1 1/2 tablespoons vegetable oil 1/4 cup chopped shallot 1 cup beef stock or 1 cup canned low sodium beef broth 1/2 cup dry white wine 1/4 cup brandy 1/2 cup[...]

1 (6 lb) beef tenderloin , trimmed of fat 1/2 cup apple cider vinegar 2 tablespoons sea salt 2 tablespoons black pepper 2 teaspoons garlic powder 2 teaspoons[...]

6 (7 -8 ounce) beef tenderloin steaks kosher salt cracked black pepper 3 tablespoons canola oil 6 tablespoons unsalted butter , chilled, divided 4 garlic[...]