Prepare coals or gas grill for direct heat. Heat to medium, about 10 minutes for gas grill (40 minutes for charcoal).
Cut the outer edge of fat on the steak diagonally at 1-inch intervals with a sharp knife. Do not cut into the meat because it will allow the juices to cook out and steak will become dry.
Place the steak on the grill rack over medium heat. Cover grill. Cook for 13-15 minutes, turning the steak once halfway, or until the steak is cooked to your preferred level of doneness.
Cut the bell pepper, yellow onion, carrot into thin strips and combine. Add olive oil, balsamic vinegar, salt, and pepper to taste and mix into vegetable strips.
Sprinkle the steak with salt and pepper. Serve with mixed vegetables and garnish with parsley.