How to Make It
Preheat the oven to 450°. In a mortar, pound the garlic with the rosemary and juniper berries to a smooth paste. Season with salt and pepper. Spread half the paste all over the inside of the lamb. Roll the lamb into a compact roast and tie it at 1 1/2-inch intervals with butcher's twine. Using a sharp paring knife, make 16 shallow slits all over the outside of the roast. With the tip of the knife, fill each slit with the remaining garlic-juniper paste.
Set the lamb in a medium roasting pan and season generously with salt and pepper. Roast the meat for 30 minutes. Add the wine and, using a wooden spatula, scrape up any browned bits in the pan. Roast the lamb for about 10 minutes longer for medium-rare meat.
Transfer the lamb to a carving board and let stand for 15 minutes before slicing. Meanwhile, pour the cooking juices into a small saucepan. Skim off any fat from the surface and simmer over moderate heat until slightly reduced. Cut the strings and carve the lamb into thick slices. Serve with the pan juices.