Prepare your smoker at 250°F. A medium smoke wood or pellets such as oak, hickory or pecan is recommended.
Trim your tenderloin. Remove the tail and chain. Tie loops around the tenderloin with butcher's twine every few inches to help it keep an even shape throughout the cook.
Slather with English mustard.
Season moderately with Meat Church Holy Cow & heavily with Meat Church Garlic & Herb. Allow to adhere for 1 hour.
Place the tenderloin directly onto the smoker cooking grate. Rotate the tenderloin during the cook if it's uneven in any way. Otherwise do not do anything. While the tenderloin is cooking, prepare the grill with a direct and high heat setup for searing and also make the horseradish cream.
Prepare the Horseradish Cream.
Mix the mayo, sour cream and add in your desired amount of horseradish to taste. Add 1–2 tbsp of Meat Church Holy Cow seasoning. Then add the juice from one cheek of lemon to brighten it up. Optionally, add truffle oil to taste if you'd like.
Prepare your grill setup for direct cooking at a temperature of over 500°F. If you do not have a grill, you can use a cast iron skillet.
Smoke the tenderloin until it reaches 110°F internal.
Remove from the smoker, lightly tent with foil and rest for 10 minutes.
After a 10 minute rest, clip off the butcher's twine. Sear the tenderloin for 2-3 minutes on 4 sides. If you desire a higher internal doneness or more crust on your tenderloin, then simply sear longer to your liking.
Remove from the grill. Slice. Enjoy with the horseradish cream!
