Combine potatoes, carrots, pepper and onion in a bowl. Season with salt and pepper, then toss with olive oil.
Use 4 pieces of heavy aluminum foil (approximately 18 x 12). Evenly place vegetable mixture in center of each piece. Top with steak.
In a small bowl mix butter, garlic, parsley, rosemary, thyme, salt and pepper. Divide and spoon onto steak.
Fold foil over, doubling ends and top, but do not wrap tightly. Leave a space for steam to gather.
Place packets on the grill and cover. Grill for about 15 minutes until vegetables are tender and meat is cooked to your liking.
You may flip the packet once on the grill toward the end of cooking to give the meat and vegetables a bit of a char.
CAREFULLY open packets and serve.