1/2 cup Dijon mustard
1 tablespoon soy sauce
1 clove garlic, minced
1/2-inch slice ginger root, minced
1 teaspoon crushed dried rosemary
1/4 cup olive oil
1 (6 1/2 pound) leg of lamb, boned
Preheat oven to 325 degrees F.
Combine mustard, soy sauce, garlic, ginger and rosemary. Gradually whisk in olive oil. With a brush, coat lamb thickly and evenly with this mixture and let stand at room temperature for 2 to 3 hours. If all the glaze is not used, baste with remainder while lamb is roasting.
Place lamb on a rack in a roasting pan and roast for 1 hour and 45 minutes or until done to taste.