Coat the tri tip in mustard and massage in the dry rub of brown sugar & spices. Smoke at 220F for 2.5 hours, spraying with apple/ cranberry juice every 30 mins.
Once the internal temperature reaches 130-135F, char on grill for 1 min each side
For the blueberry bourbon sauce:
Sauté red onion & garlic in a tbsp of butter in a medium pot until translucent, about 5 mins.
Add blueberries & all other ingredients, bring to a gentle simmer for 30 mins, use an immersion blender to blend until smooth
Adjust seasonings to taste, for a more zip taste add more vinegar, for sweeter add more sugar & ketchup