Melt 1/4 cup butter in medium pan. Stir in 1/3 cup flour; cook until mixture is bubbly. Gradually add 10 3/4 ounce can condensed chicken broth and 1/2 cup milk.
Cook over medium heat until mixture boils and thickens. Add 1 cup thawed frozen peas, 1/2 cup shredded cheddar cheese, 1/2 or 1 cup sliced fresh mushrooms and 2 cups cubed, cooked chicken. Open 2 ounce jar chopped pimiento (reserve 1 tablespoon and add rest to chicken). Simmer chicken a la king, stirring now and then.
Separate 7.5 ounce can refrigerated biscuits into 10 biscuits. Make 1" depression in each biscuit. Combine 1/2 cup shredded cheddar cheese, reserved pimiento and 1 teaspoon parsley flakes. Place a heaping teaspoon of this mixture in each biscuit. Pour hot chicken mixture into 2 quart casserole; top with biscuits. Bake at 375 degrees 17 to 27 minutes or until biscuits look done.