Cube chicken. Mix 3/4 cup flour, oatmeal, baking powder, oil, milk and egg white together (will make a wet biscuit dough). In oiled crock pot, mix chicken, peas and carrot and corn. Heat 1 1/2 cups water, onion, poultry seasoning and cream of chicken and a fatty piece of chicken on medium heat. Mix 1/2 cup cold water and 1/4 cup flour together to make a white sauce.
Gradually pour white sauce into water-chicken mixture, stirring constantly. Continue stirring until mixture forms gravy. Pour gravy over chicken, peas, carrot mixture and slightly stir. Drop biscuit dough in 1/4 cupfuls onto top of crock pot mixture. Cover and leave 1/4 inch vent (so steam can escape). Cook on high 4 to 5 hours, until biscuits are slightly brown.