I have been assured that what makes Irish Stew so awesome is its simplicity. So this is really straightforward, and I must say, it's pretty damn good that way.
3 lbs. lamb, cubed
1/2 cup onions, sliced
6 medium potatoes, diced
2 carrots, diced
2 or 3 white turnips, peeled and cubed
Lightly dredge lamb in flour, salt and pepper. Brown in cast iron pan, transfer to soup pot. In same cast iron, cook onion until softened and golden, transfer to pot with lamb. Add boiling liquid just to cover. (If I get a bone-in piece of lamb, I do a quick stock for this part by breaking the bone open and boiling it with onion, celery and carrot then straining; otherwise you can use broth or even — per the recipe — water.) Cover pot, simmer on low for two hours. Add veg, cook 20 minutes. Add salt and pepper to taste. Thicken if necessary, but I just try to adjust the heat on the veg-cooking part to reduce the liquid to the appropriate thickness.