Heat a Dutch oven over medium-high heat. (If the brisket is very well trimmed, add 1 tablespoon of oil to coat the bottom of the pan. If the brisket has fat on it, the oil is not necessary). Add the brisket and cook until browned, about 8 minutes, turning once. Add the celery and onion and cook, stirring, 2 minutes. Add the water, reduce heat to medium-low, cover and simmer 3 hours.