Leftover mashed potatoes are mixed with white cheddar cheese to form the top crust for this British pub-food staple. Ground beef is traditionally used, but lean ground turkey will work, as well. Brown the crust under the broiler for a minute or two, if you like.
For an easy, satisfying, and healthy chicken casserole dinner, check out this lightened up version of one of our most popular chicken dishes of all time.