Trim any excess fat from the tri-tip roast. Pat it dry with paper towels to ensure a good sear later on.

In a small bowl, combine kosher salt, black pepper, garlic powder, onion powder, smoked paprika, and dried thyme. If using the optional rub ingredients, mix brown sugar, chili powder, and cumin in a separate bowl.

Rub the tri-tip with olive oil to help the spices stick. Then, generously coat the meat with the spice mixture. For added flavor, apply the optional rub mixture as well.

Place the seasoned tri-tip in a zip-lock bag or a covered dish and let it marinate in the refrigerator for 2-4 hours. This step is optional but will enhance the flavor.

Fire up your Green Mountain Grill to 225°F. Choose hickory or mesquite wood pellets for a robust smoky flavor, or use apple or cherry for a milder, sweeter smoke.

Place the tri-tip directly on the grill grates. Close the lid and smoke for 2-3 hours, or until the internal temperature reaches 135°F for medium-rare. Use a meat thermometer to check the temperature.

Every hour, baste the tri-tip with beef broth or apple juice to keep it moist and add extra flavor.

Once the tri-tip reaches the desired temperature, remove it from the grill and wrap it loosely in aluminum foil. Let it rest for 15 minutes to allow the juices to redistribute.

Place the rested tri-tip on a cutting board and slice against the grain for maximum tenderness. This means cutting across the muscle fibers rather than parallel to them.