Preheat oven to 350 degrees F. Spray a medium (about 1 ½ quart) casserole dish with cooking spray.
In the prepared dish, whisk together condensed soup and milk. Stir in uncooked chicken, mushrooms, bell pepper, and pimientos. Season with salt and pepper, to taste.
Bake uncovered at 350 degrees F for 40-45 minutes, stirring every 15 minutes to ensure even cooking.
Remove from oven when the dish is hot and bubbly and the chicken is cooked through.
Garnish with fresh parsley just before serving.
Serve over hot biscuits, cooked rice, or pasta.
Notes
Cooking just for Two? Cut the ingredients in half and bake in a small dish. The cooking instructions remain the same.To Make Ahead:
You can assemble the casserole a few hours in advance and keep it covered in the refrigerator until you're ready to bake it.
To freeze for a later date, I suggest baking the dish first (according to the recipe instructions). Allow the chicken to cool to room temperature before transferring to an airtight container or zip-top freezer bag. Store in the freezer for up to 3 months. When ready to serve, just thaw in the refrigerator overnight and reheat gently in the oven at 350 degrees until warm, or reheat on the stovetop over low heat until warm.