Brown mushrooms and onion with butter in roasting pan. Add tenderloins (tied) and remaining ingredients to roasting pan. Cook 45 min1 hour at 350 degrees. Use meat thermometer to check internal temperature (160 degrees for medium).
Remove meat from pan and let rest while you add 2-3 T. cornstarch mixed with water to thicken gravy.
Slice and serve with gravy
Go to full version of