Preheat oven to 375 F.
Place fish in a greased casserole.
Make up stove top stuffing.
Prepare a white sauce:
Melt butter in a pot, whisk in flour. Slowly stir in the milk. Add in salt and salmon spice. Cook until thickened, stirring constantly.
Cover fish with sauce, and top with Stove Top stuffing.
Top with grated cheese (your choice, although a white aged is recommended)
Bake for 20-30 minutes, until cheese is melted.