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, sauté the onion in the butter over medium heat until tender.

Step 4

Stir the flour, the salt, and the pepper into the butter mixture until blended.

Step 5

Gradually stir the broth into the butter mixture and bring to a boil.

Step 6

Boil the butter mixture, while stirring, until thickened and bubbly, about 2 minutes.

Step 7

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

Step 8

Transfer the chicken mixture into the prepared baking dish.

Step 9

Sprinkle the top of the casserole with the almonds.

Step 10

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

Step 11

Serve.