Grandma's Easy Stuffing

For each 6 oz box of Stove Top Stuffing (Chicken or Turkey), saute 1/2 an onion and 1 rib of celery (both small dice) in 2 Tablespoons butter on medium low heat for 10-15 minutes.  While the onion and celery are cooking, boil 1 1/2 cups water.  When the onion and celery are done, pour the stuffing mix and boiling water into the onion/celery mixture.  Stir well.  Remove from heat.  Cover.  Let sit for five minutes.  Fluff with a fork and serve!