Place broccoli halves in a large microwave safe bowl or casserole dish. Add the water and oil, and toss to coat. Cover the dish with an upside down plate, and microwave 2-5 minutes until tender crisp when pierced with a fork.
Remove from microwave, uncover, and sprinkle with garlic powder. Toss to coat.
Preheat gas grill to medium-high. Place cut and steamed broccoli directly on the grill grates, cut side down, and grill until marks start to appear, about 5 minutes. Turn, and continue to grill on the other side for about 5 minutes more. Turn, and grill buds for a couple minutes to get some extra charring on them.
Serve, sprinkled with fresh ground pepper if desired. Or, cut into smaller florets to toss in salads.