Most people think Irish Stew has carrots in it, among other vegetables, and probably be made with beef. According to the Joy of Cooking, however, it is lamb, onions, and potatoes. That's it. You probably expect your stew to be brown, too. This isn't, but it's really good anyway.

Irish Stew

6 medium potatoes, sliced 1/4 inch thick (about 2 pounds)
4 large onions, sliced 1/4 inch thick (about 1 1/2 pounds)
3 pounds boneless lamb neck or shoulder, no fat
1 teaspoon salt
Pepper
1/4 teaspoon dried thyme

Spread 1/2 of the potatoes in a 4 to 5 quart casserole that can go on the stove top. Cover with 1/2 of the onion and all of the lamb with half of the salt, pepper, and thyme. Add the rest of the potatoes and onions. Cover with cold water and bring to a boil. Reduce the heat, cover, and simmer for 1 1/2 hours until potatoes are tender. Can be cooked in the oven at 350 degrees.

There is a marvelous food history blog called The Old Foodie where I found a similar recipe.

A Baked Irish Stew

"Fill an brown upright Nottingham jar with alterate layers of mutton (or beef), sliced potatoes, and mild onions; and put in water and seasoning; cover the top closely with whole potatoes (pared), and send the stew to a moderate oven. The potatoes on the top should be well cooked and browned before the stew is served. We have not considered it necessary to try this receipt, which was given to us by some friends who keep an excellent table, and who recommended it much. It is, of course, suited only to a quite plain family dinner. The onions can be omitted when their flavour is not liked."