Step 1

Preheat the oven to 350 degrees F.

Step 2

Grease a 2 1/2-quart baking dish.

Step 3

In a large saucepan over medium heat, add the onion and the butter and sauté until tender.

Step 4

Stir the flour, the salt, and the pepper into the onion until blended.

Step 5

Gradually stir the chicken broth into the onion mixture.

Step 6

Bring the broth mixture to a boil and cook, while stirring, until it thickens and is bubbly, about 2 minutes.

Step 7

Stir the half-and-half, the cubed chicken, the cooked rice, the mushrooms, the pimientos, and the parsley into the broth mixture and cook until heated through.

Step 8

Pour the chicken mixture into the prepared baking dish and sprinkle with the almonds.

Step 9

Bake the casserole until bubbly, about 30-35 minutes.

Step 10

Serve.