Step 1

Preheat the oven to 350 degrees F.

Step 2

Lightly grease a 13x9-inch baking dish.

Step 3

In a shallow oven-safe pan, bake the almonds until toasted, about 5-10 minutes.

Step 4

In a large bowl, stir the toasted almonds, the chicken, the onion, the celery, the pimiento, the water chestnuts, the mushrooms, the salt, and the pepper together.

Step 5

In a separate bowl, stir 1 cup of the cheddar cheese, the mayonnaise, the sour cream, and the lemon juice together until blended.

Step 6

Stir the chicken mixture into the cheese mixture.

Step 7

Spread the casserole filling into the prepared baking dish.

Step 8

Sprinkle the top of casserole with the remaining cheddar cheese, the potato chip crumbs, and the parmesan cheese.

Step 9

Bake, uncovered, until heated through, about 30 minutes.

Step 10

Serve.