Chop the fresh mint as finely as you can. Put in a small glass and pour on the vinegar and sweetener (optional).
Mix together with a fork and allow to infuse while you cook the roast lamb.
Remove the leg of lamb from the fridge while you preheat the oven.
Place the leg of lamb on an oiled roasting dish.
Dry the top of the roast with paper towels.
With a sharp knife, make small cuts into the meat and press pieces of fresh rosemary into the cuts.
Sprinkle with a moderate amount of salt (not to excess) over the entire top of the meat.
Roast at 180C/350F for the following times.
Well done lamb 30 minutes per 450g/ 1 lb plus 30 minutes.,
Whichever way you choose to cook your lamb, always remove the meat from the oven, cover with foil and a few tea towels to keep warm for 10 minutes. This allows the meat to relax and the juices to settle.
There are negligible carbs from the sugar-free mint sauce.