Rinse the thyme, rosemary, and cilantro.
Pat dry.
Finely mince the herbs and garlic. Set aside.
Cube the butter and set aside.
Wash, peel, and dice the potatoes.
Mix with the herbs and butter.
Make sure everything is coated well. Sprinkle with salt.
Take a large piece of foil paper, and to the center, add potatoes.
Wrap the potatoes into a packet, leaving a small opening.
Add the water to the opening.
Then tightly wrap the package. Use as much foil paper as needed.
Set on a hot grill for 20 minutes, or until fork tender.
Let cool slightly before serving.