Any suggestions for how to turn left-over lamb roast into a stew? I don’t have any left-over drippings or gravy, so I might have to use beef OXO for the gravy?
I take it that means you don’t have any lamb stock. Or vegetable? I’d use either in preference to beef stock, personally. Options without stock at all… You could make a tomato-based sauce, make it a kind of Mediterranean or North African style arrangement. You could make a Chinese style stew, with soy sauce. You could… go back in time and make more gravy…
Mind you, if it’s a good flavoursome cut and some tasty vegetables, not having any stock isn’t the end of the world. How well did you cook it? If it was rare or medium to begin with, cube the leftover meat and rebrown it on the cut sides, then deglaze the pan with some red wine or sherry (seriously, sherry and lamb: a misunderestimated combination), put the meat and the liquid into a bowl, start your vegetables by frying them lightly until the bottom of the pan is starting to get brown again, add a little flour to thicken the sauce, return the meat and liquid (which will have increased in volume), stir it about, then just add some water. For the vegetables, I would personally definitely include carrots, as they will help to bring out the flavour of the meat. Soy or Worcestershire sauce, crumbled dried mushrooms or a couple of anchovies dissolved into it will also help the sauce to be more flavoursome.
Yeah- I made lamb and barley stew after Easter with leftover lamb, and if you brown up the cubed pieces, add some tomatoes and vegetables and spices, and let it cook a good couple of hours, you really won’t need any stock. I’d just follow the above advice, except I’d add barley- yummy.
I may have even put in a cube or two of chicken bullion… so it probably doesn’t matter what flavor you use, if you wanted to use bullion, as long as it’s not too much.
My advice: carve off the remaining lamb, and use in a sandwich tomorrow. Boil the bone up to make some stock for gravy with the next roast.
Then make a lamb broth like my gran used to make, with a gazillion portions for the freezer 
…
Go to a butcher, buy a lamb shoulder, and if necessary get them to cut it into pieces that’ll fit in the largest pot you have. Fry up big piles of chopped veg in butter (leeks, fennel, onions, garlic, that kind of thing), then add the lamb and cover with water, adding salt. Bring to the boil, and simmer gently for several hours. Take the lamb out, and rake the meat off with a fork. Add the meat back to the pan, along with some pearl barley (250g will suffice for 10 hearty portions) and simmer for another 20-30 minutes, until the barley is cooked.
Yes. Og yes, definitely do the barley thing. It’s a long time since I had barley with my lamb, but checking back into this thread reminds me of how much I love it. Must buy barley. You can also make a barley risotto-type thing and serve it with the lamb (or anything else, or on its own) just sliced, rather than stewing the whole lot together. I also agree with Alice The Goon about the chicken stock in preference to beef.
You could use wine or beer instead of stock, too.