Place all ingredients in a food processor or blender and blend until well combined. Do not over blend.
To make the salad:
In a small bowl, combine BBQ seasoning ingredients.
Rub the tri-tip with olive oil and BBQ seasoning.
Heat a skillet or griddle pan over medium/high heat for 2 minutes, this will assure the skillet is hot and ready. Add oil and then the steak.
Sear for 3-4 minutes on each side for medium rare. Sear for 4-5 minutes on each side for medium. And Sear for 5-6 minutes for well done. Remove from the pan. Let the meat rest for 5 minutes before slicing. This will seal in the juices.
In four individual plates, assemble: lettuce, tomatoes, corn, bell pepper, avocado, and onion. Top with sliced steak. Drizzle with vinaigrette.