In a medium sized bowl, add the red potatoes, carrots, bell peppers, and red onion. Add salt and pepper to taste and toss with olive oil.
Place four 18x12 inch pieces of heavy aluminium foil on counter. Evenly divide vegetable into four portions and place each portion onto a piece of foil each. Do the same for the steak.
To make the garlic herb butter: In a small bowl add the butter, parsley, garlic, rosemary, thyme and salt and pepper to taste. Divide evenly and place on top of the steak. Double fold the top and ends of each piece of foil, leaving space for steam to gather.
Place packets on the grill and cover. Grill on a medium heat for 15 minutes or until steak is cooked through and veggies are tender. Carefully open packets and serve.