Mushroom Stuffed Baked Red Snapper

My gf is on winter recess so we've been cooking up a storm. She wanted to make a baked stuffed fish and I was a little hesitant since I'd only grown up with 3 basic meats (chicken, pork, and beef) and had never cooked a whole fish before. She went to the fish market, picked out a nice fat red snapper, and found the recipe on Food Network. We hungrily devoured it and only left behind the head and bones (perfectly intact).

Ingredients

4oz - Baby Bella Mushrooms (chopped)

2 tbsp - Unsalted Butter (divided)

2 1/2 tbsp - Yellow Onions (minced and divided)

1/4 cup -Flavored or Italian Bread Crumbs

1 - Egg (beaten)
1/2 tbsp - Soy Sauce

1/2 tbsp - Parsley (chopped)
Kosher Salt
Freshly Ground Pepper
2lb - Red Snapper (whole, gutted, scaled, and cleaned)

1/4 cup - White Wine

3/8 cup - Water

1) Preheat oven to 350 degrees.

2) Clean and chop the mushrooms.
3) In a small skillet, melt 1 tbsp butter (you should have 1 tbsp left) and 1 1/2 tbsp of onions (you should have 1 1/2 tbsp left) and saute for 4 minutes.
4) In a large bowl, combine the sauted butter/onion mixture with the mushrooms, bread crumbs, egg, soy sauce, chopped parsley, salt, and pepper.
5) In a glass pyrex, spoon as much of the mixture into the fish and secure the openings with toothpicks.
6) Sprinkle both sides of the fish with salt and pepper.
7) With the remaining mixture, make a bed under the fish and add the remaining butter, onion, wine, and water (to create a water bath).
8) Bake for 50 minutes.