Preheat the oven to 250 degrees F. Combine kosher salt, black pepper, and cumin in a shallow dish. Roll roast in seasonings, coating well. Preheat a cast iron grill pan over high heat. Once the pan is hot, brush the roast with the olive oil, and sear on all sides, approximately 8 to 10 minutes total cooking time.oll roast in seasonings, coating well. Preheat a cast iron grill pan over high heat. Once the pan is hot, brush the roast with the olive oil, and sear on all sides, approximately 8 to 10 minutes total cooking time.