Preheat your smoker to 225°F.

Gently press your beef seasoning into the tri-tip.

Place the tri-tip on the grates of your smoker and smoke it until it is 5-10 degrees from your desired temperature (see the above information).

Remove the tri-tip from the smoker and put it in a pan of hot butter with the rosemary sprig.

Sear the tri-tip for 2-3 minutes on each side. Remove from the pan and let it rest for 15 minutes, then slice and serve!