I've eaten Irish stew in private homes and public eating places all over Ireland, north and south, probably twenty-five or thirty examples in all, and no two have been alike. Along the way, I've come to believe that the construction of this dish should adhere to a few simple guidelines: 1. Use the best quality lamb you can find, but use the less expensive, more flavorful cuts. 2. Keep it simple: the world won't end if you add carrots or fresh thyme, but don't throw too many different things in the pot. 3. Cook it very slowly; an old adage has it that "a stew boiled is a stew spoiled." 4. Always make the stew the day before you serve it; a night in the refrigerator really will improve it. 5. The finished product should be thick enough that you can stand a spoon in it.
Preheat the oven to 250°F.
Put the lamb, potatoes, parsley, and onions into a heavy casserole with a lid and season with salt and pepper. (Or layer the ingredients, starting and ending with a layer of potatoes, and seasoning each layer to taste).
Add 2 cups of water or enough to barely cover the ingredients. Bring to a simmer over low heat (do not boil), then cover and put into the oven. Cook for 2-1/2 to 3 hours or until the meat is very tender and the stew is thick, adding a little water if the stew dries out too much.
Photo: Christopher Hirsheimer