Late on this, but I fix lamb similar to VFTB's way.
I prefer a leg of lamb, so there's leftover for stew, but I rub olive oil on it, then cover with cracked pepper and garlic powder, and cook to just medium rare. Overcooked lamb is terrible and a waste of money.
Use the leftovers....cut into chunks, put in the bottom of a crock pot, add in layers chunks of onion, celery, mushrooms, potatoes, carrots, and a pachage of uncooked frozen peas. Pour a bottle of Guiness over it. And just let it cook all day.
About 30 minutes before serving, whisk some flour- about 2 tblsp into a cup of water. Add to the stew. (I pour it through a mini-strainer to make sure there are no lumps.) Add a tsp or two of beef bouillon granules.
Stir every thing together, let it thicken up....taste the gravy and add salt and pepper at this time. You can add pepper when you dump it all in first thing, but don't add the salt until the end because of the beef bouillon is salty. You can always add salt....it's tough to decrease the saltiness if you've added too much at the beginning.
May have to do more of the flour/water mix ....I don't ever measure stuff like that, I'm just estimating.
serve with a green salad and a chunky white bread...preferably Irish soda bread, but French or Italian bread works great too.