Slow-cooked dish made with lamb or mutton and potatoes (5,4)
I believe the answer is:
irish stew
(Other definitions for irish stew that I've seen before include "Mutton and vegetable dish" , "Dish of meat, onions, potatoes etc" , "Traditional simmered dish of mutton, potato and onions" , "Local dish of meat, potatoes and onions" , "casserole" .)