Mustard-Crusted Prime Rib with Madeira Glaze

Directions

1. Let roast stand at room temperature for 1 hour. Preheat oven to 450°. Combine mustard, garlic, brown sugar, salt and, if desired, peppercorns; brush evenly over top and sides of roast but not over bones (mixture may seem loose but will adhere). Place bone side down on a rack in a shallow roasting pan. Place pan on middle oven rack; immediately reduce heat to 350°. Roast 1 hour.
2. Toss potatoes, carrots, onion and fennel with next 5 ingredients. Arrange vegetables in a single layer in a 15x10x1-in. baking pan on lowest rack of oven. Roast meat and vegetables, stirring vegetables midway through baking, until meat reaches desired doneness (a thermometer should read 135° for medium-rare, 140° for medium and 145° for medium-well), about 1-1/2 hours. Cover roast loosely with foil during last 30 minutes to prevent overbrowning. Let stand 15 minutes before carving.
3. Meanwhile, for glaze, combine balsamic vinegar, Madeira wine and brown sugar in a small saucepan. Bring to a boil over medium-high heat; cook until reduced to 1/2 cup, about 15 minutes. Let glaze cool to room temperature. Serve roast with vegetables and glaze and, if desired, pink peppercorns and fennel fronds.