Make small incisions in leg of lamb and insert the slices of garlic in each incision.
Rub olive oil, rosemary around the lamb and season with salt and pepper.
In large non-stick pan, brown leg of lamb.
While the lamb is browning, you can prepare the slow cooker/crock pot. Pour the stock and soy sauce into the slow cooker/crock pot. When the lamb is finishing browning add it to the slow cooker/crock pot.
Cover and cook for 8-10 hours on low setting.
Remove from slow cooker/crock pot and let rest 15 to 20 minutes before slicing.