Leg of lamb is delicious any time of year, but particularly in the spring when it is most tender and succulent. Lamb roasted with herbs and mustard is a dish fit for the finest occasion. Press the herb mixture into the slits in the meat, brush it with mustard, and let it macerate to allow the flavor to permeate the lamb.
8 servings (serving size: 3 ounces lamb and 1 tablespoon sauce)
Combine first 3 ingredients, stirring well. Unroll roast; trim fat. Reroll roast; secure at 1-inch intervals with twine. Cut 10 (1/2-inch-deep) slits in surface of roast; stuff thyme mixture into slits. Sprinkle with 3/4 teaspoon salt and pepper. Brush mustard over roast. Cover and chill 12 hours.
Preheat oven to 425°.
Arrange 3 rosemary sprigs crosswise on the rack of a broiler pan, and top with roast. Arrange 3 additional rosemary sprigs on top of roast. Bake at 425° for 50 minutes or until a thermometer registers 145° (medium-rare) or desired degree of doneness. Discard rosemary. Let roast stand 20 minutes before slicing.
Combine water and broth; add to broiler pan. Cook over medium heat; bring to a boil, scraping pan to loosen browned bits. Cook 4 minutes or until mixture measures 1/2 cup; stir in remaining 1/2 teaspoon salt. Slice roast; serve with sauce.