Preheat oven to 375ºF.
In 13 x 9-inch pan, combine uncooked rice mix with seasonings packet, celery, mushrooms & water.
Dot the top with 2 tbsp. butter. Wash hens & pat with paper towels.
Using kitchen shears or a sharp knife, cut hens in half lengthwise down side of breastbone & backbone.
Arrange pieces, skin-side up, on top of rice. Brush with melted butter.
Cover with foil and bake 1 hour; uncover and bake 30 minutes longer, or till hens are golden brown.
If using dark pans reduce heat to 350ºF.
4 servings.
Note: About 2 lb. chicken pieces may be substituted for the Cornish hens.