Crawfish Etouffee

1 stick of butter (1/4 lb)
1/2 green bell pepper, chopped
1/2 onion, chopped
2 stalks celery, chopped
1 T. Creole seasoning (I use Zatarain's)
1 pound crawfish tails (frozen seafood section, already peeled, etc.)
3/4 cup water

Melt butter over medium heat. Add pepper, onion, celery, seasoning, crawfish, and water to pot. Bring to a boil. Cover with lid, simmer 10 minutes stirring occasionally. Remove from heat and let stand 10 minutes with lid still on. Serve over rice.