Stovies is a Scottish potato dish designed to use up leftovers, particularly those from a roast dinner: items such as potatoes, meat, veg, dripping, gravy, etc. It can be prepared from scratch, too, without leftovers.
The dish is cooked on top the stove in a pot, as opposed to in an oven, and thus the name "stovies."
The essential, omnipresent ingredient is potato, but it almost always has onion in it as well. It may have pieces of leftover meat added to it -- diced chicken, diced lamb, minced beef, corned beef, sausages, bacon -- even game such as grouse. Occasionally, carrots are added.
Stovies can be prepared in several ways. In some forms, it is almost a Scottish version of "Gratin Dauphinoise" or Scalloped Potatoes; it others, it is almost like American hash.
A few examples:
1) Potatoes are peeled and sliced, put in a pot with butter, salt and a small amount of water, and simmered until done;
2) Onions and sliced potatoes are fried in dripping (beef or lamb), or oil, then leftover slices of are meat added, with water, and it is simmered;
3) Fat is melted in a pan, then layers added of raw potato, onion, and meat, then enough stock (can be made from OXO cubes), water or thinned gravy to cover is added (some add less, preferring their Stovies drier.) Cook covered on top of stove for about 30 minutes, shaking occassionally, until all liquid is absorbed.
Some people prefer to use butter instead of dripping. As the water is absorbed, some people like to add a small amount of milk. Some fry the onions first in butter or dripping before adding the potatoes and water; some don't and just simmer the onions in the water with the potato.
If sliced too thinly they will fall apart. Some like to make sure that some slices will, so the dish will be more "stick to the fork."
The usual seasoning is salt and pepper. If garnished at all, parsely or chives can be used.
Stovies are sometimes served with oatcakes on the side, particularly in Aberdeen, Scotland.