Rub the tri-tip with olive oil, salt, pepper, and garlic powder.
Place the roast on a baking sheet and cook for 15-20 minutes or until the internal temperature reaches 130 Fahrenheit for medium-rare.Let the tri-tip rest for 10 minutes before slicing against the grain.
Toast the rolls if desired.Layer provolone cheese, arugula, red onion, and thinly sliced tri-tip on each roll.Drizzle with chimichurri sauce or your favorite sauce.