Marinate fillet in your choice of Lawry bottled marinade for 15-30 minutes (I like herb/garlic and lemon/peppercorn).
Fire up Traeger. Set at 300F.
Cook fillet for 15 minutes (no need to rinse off the marinade).
Increase to 375F.
Flip and cook 15 more minutes or until all but center is done (it will finish cooking while resting).
Time will vary depending on thickness but the above time works for medium thickness fillet (1 1/2 to 2 inches).
Apple or cherry pellets are my preferred wood.