Combine the cracked pepper, salt, sugar, paprika, and onion. Mix well then store in an airtight container.
Chimichurri
Blanch the basil and wild garlic in boiling water for 30 seconds, then remove and plunge into a bowl of iced water.
Place the garlic and chili, basil, and wild garlic into a blender along with the vinegar and olive oil then blend until smooth. Adjust the seasoning with lemon juice and salt.
Smoked Tri Tip
Prepare the tri-tip by trimming the fat and removing the sinew. Sprinkle a light coating of the rub all over the tri tip then set aside in a cool place for an hour.
Preheat the smoker to 230 degrees F (110 degrees C), then add some hickory chunks.
Place the rubbed tri tip in the smoker and smoke for 90 minutes or until the internal temperature reaches 135 degrees F (56 degrees C).
In a skillet add the butter, garlic cloves, and rosemary then bring to a gentle simmer.
Remove the tri tip from the smoker then add to the skillet. Spoon the flavored butter over the tri-tip for several minutes to sear the outside. This is a variation on the reverse sear method using frying rather than grilling to finish.
Remove the tri tip from the skillet and rest in a warm place for 30 minutes before serving.
Serve the tri tip sliced against the grain, topped with the chimichurri sauce.