For the au jus and while the lamb is roastingwe''ll braise the garlic:
3headsgarlicusing microwave method, cloves separated and peeled
15ouncesBeef stockor enough to cover garlic cloves
3freshthymesprigs
1bay leaf
Finish the Au Jus:
15ouncesBeef stockor as needed to make two cups of liquid to the broth from the cooked lamb
1cupdry sherry
4teaspoonsfresh thyme
Salt and fresh ground pepper
Instructions
For the Lamb:
Cut about 24 small shallow slits into the surface of the lamb. Insert a sliver of garlic and thyme sprig into each slit. Cover and refrigerate up to one day.
Preheat oven to 400 degrees. Sprinkle lamb with salt and pepper and place in a roasting pan.
Roast for about 1 1/4 hour for rare with the bone in, or until a meat thermometer registers 130 degrees. A boneless leg will take about one hour
For the Au Jus
In a sauce pan over medium heat, combine the garlic cloves, stock to cover barely, thyme and bay leaf. Cover, bring to a boil and simmer over medium heat until the garlic is tender. About 25 minutes. Remove from heat and using a slotted spoon, transfer the garlic to a small bowl. Strain the cooking liquid into a 2-cup measuring cup.
Finish the Au Jus:
Add stock to the strained liquid to measure two cups. Add the sherry and bring to a boil. Boil uncovered, over high heat until reduced by one-third. Add the chopped thyme and reserved braised garlic cloves. Adjust the seasoning with salt and pepper and keep warm.
When the lamb is done, remove from oven and cover loosely with foil. Let rest for ten minutes. Carve the lamb and place on individual dinner plates. Spoon some of the sauce along with garlic cloves over each serving of lamb. Serve immediately.