Bring chicken broth to a boil; add carrots, onions, celery, mushrooms and garlic;
simmer 10 minutes. Add cubed chicken meat and peas; simmer 5 minutes more. Mix cornstarch
with cold water in measuring cup; add slowly until chicken mixture has consistency of
gravy. Remove from heat; cool.
To Freeze: Pour into round casserole dish (2 qt capacity). Cover with plastic wrap and then aluminum foil.
To Reheat: Thaw casserole before cooking. Place in 400-degree oven for 25 minutes.
Remove from oven and place uncooked biscuits (either from "tube" or scratch
in slightly-overlapping circles on top of casserole. Return to oven and bake 20 to 25
minutes more, until mixture is bubbling and biscuits are golden brown.