How to Roll a Boneless Leg of Lamb
Ask your butcher to remove the bone from a leg of lamb (the bones can be kept for pets or making a gravy). You could also buy a “pre-butterflied” leg.
Skin side down, unroll it on a tray, and if necessary, make some additional slices across the leg so that the meat has a general even thickness. Do not cut through to the skin.
Fill the leg - meat side - with a generous amount of marinade or filling and massage in.
Roll the leg as if the bone is still in, so it resembles the original shape. This may take 1 or 2 goes to correct.
Use kitchen twine to tie the leg at 4 cm intervals. The ties do not have to be excessively tight, so do not worry about slipping strings. Just make sure it is secure enough to keep the leg rolled and intact during cooking.
Trim excess string.
Rub on any filling that has escaped, then drizzle with oil, season with salt and it is ready for the oven.