At least 45 minutes before grilling (or up to 24 hours ahead), generously season the tri-tip on all sides with kosher salt. Place on a wire rack set over a baking sheet and refrigerate uncovered if doing overnight. If doing 45 minutes, leave at room temperature.

In a small bowl, combine smoked paprika, garlic powder, onion powder, black pepper, dried oregano, and cayenne (if using). Stir to combine.

Mix olive oil and pressed garlic paste together, then rub all over the tri-tip. Pat the dry spice rub generously over all surfaces of the roast, pressing it in firmly so it adheres.

For charcoal: Build a two-zone fire — pile coals on one side for high direct heat, leaving the other side empty for indirect heat. Add a small handful of red oak or hickory wood chips directly to the hot coals for smoke. For gas: Turn one burner (or two) to high and leave the remaining burner(s) off. Preheat the grill with the lid closed for 10 to 15 minutes until the direct zone reaches 450 to 500°F.

Place the tri-tip fat-side up on the indirect (cool) side of the grill. Close the lid and cook for 20 to 25 minutes, until the internal temperature reaches 110 to 115°F for medium-rare (or 120°F for medium).

Move the tri-tip directly over the hot zone. Sear 2 to 3 minutes per side, turning once, until a deep mahogany crust forms and the internal temperature reaches 125°F for medium-rare or 135°F for medium.

Transfer the tri-tip to a cutting board, tent loosely with foil, and rest for 12 to 15 minutes. Do not skip this step.

Locate the grain of the meat — note that it runs in two different directions across the tri-tip roast, meeting roughly in the middle of the triangle. Slice thinly against the grain in each section, adjusting your angle as the grain direction changes. Slice to about 1/4-inch thickness for the most tender bites.

Arrange slices on a platter, spoon any resting juices from the cutting board over the top, and garnish with fresh parsley if desired. Serve immediately.