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.
White truffle oil has an intense earthy flavor that wakes up ordinary mac and cheese. We also get extra flavor by steeping the milk with onion and bay leaf.
