This cottage pie recipe is fantastic. I usually replace the celery with other veggies - peas, courgettes, mushrooms. I make it about once a week as my toddler loves it - sweet potato also works a charm instead of potato.
English Cottage Pie - 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. Makes 6 servings.