We had something very similar last Sunday but instead of lamb leg, we had shoulder (more flavour).
I wouldn’t roast it in the oven after slow cooking as that will dry out the meat. Simply sear the joint in a frying pan prior to slow cooking and it will give the gravy a richer flavour.
Not cooking tonight, bairn is with my mother for the night so a rare night out with the missus, we're off to Bar 44 for some grub. A couple of drinks before hand too.
Somewhere shiney for her and hopefully brewdog for me.