Place 1/4 cup of stuffing mix in food processor or blender. Whirl until fine crumbs. (Or place stuffing mix in paper bag and crush with rolling pin.) Sprinkle on waxed paper. Dip chicken breasts in stuffing mix to coat.
Heat 2 tablespoons of the butter in a small skillet over medium heat. Add the green onion and apple; sauté for 4 minutes or until softened. Stir in the remaining 1-1/2 cups of stuffing mix and 1/2 cup water until the mixture is well combined.
Preheat oven to 400 degrees F. Spoon stuffing mix into 11 x 7 x 2-inch baking pan, shaping into an oval, the size of chicken breasts. Arrange chicken breasts in a single layer over stuffing to cover. Sprinkle with salt. Melt remaining 1 tablespoon butter; drizzle over the chicken.
Bake in preheated 400 degree F oven for 25 minutes or until chicken is no longer pink in center. Serve hot.