For a foolproof beef tenderloin with caramelized onion and mushroom stuffing, follow these key steps. Tap the link in our profile to sign up for a free trial for the full recipe and more.⁠ ⁠ #americastestkitchen #atkgrams #beeftenderloin #tenderloin #beef #mushroom #onion #christmas #dinnerparty #diy #foolproof #recipes