Add all of the ingredients, except the garnish, to a large mixing bowl. Stir everything together, just until evenly combined.
2-3 tilapia filets, 2 1/2 cups steamed white rice, 3/4 cup teriyaki sauce, 1/3 cup heavy cream, 1 12 oz pkg broccoli slaw mix, 2 4 oz cans mushrooms (stems & pieces)
Lightly spray an 8x8" baking dish with non stick cooking spray. Transfer the casserole mixture to the dish, and use a spatula to spread it out in an even layer.
Bake, uncovered, at 375° for 15 minutes.
Carefully remove the hot dish from the oven, and using a fork to fluff the mixture, give it a bit of a stir. Sprinkle a little extra teriyaki sauce out overtop, if desired.
Return the dish to the oven and bake for another 15 minutes.
Sprinkle almonds and green onions evenly out over top of the casserole, and serve warm.
1/3 cup slice almonds, 2 tbsp thinly sliced green onions