Hi there
I only ever do roast lam in the slow cooker now, it's devine and so simple!
All I do is cut my vegies up (I usually only put potatoes and carrots in there and boil peas, corn cauli and brocolli after), chuck the vegies in the slow cooker and put the meat on top.
I don't put any water in and it turns out perfect every time and the meat is so tender!
Good luck!
I do mine the same but we add pumpkin and sweet potato too. Sometimes I put the veggies in the oven once they are cooked to crisp up the outside.