Corned Beef Brisket with Roasted Vegetables and Lemon-Mustard Sauce

Position oven racks in upper and lower thirds of oven. Heat oven to 350°F (175°C). Place corned beef brisket in roasting pan; sprinkle garlic, contents of seasoning packet and peppercorns around brisket. Add water; cover tightly with aluminum foil. Braise in upper third of 350°F (175°C) oven 3 to 3 1/2 hours or until brisket is fork-tender. Meanwhile, place carrots, parsnips and cabbage on rimmed baking sheet. Drizzle with oil and toss gently to coat. Season with salt and ground pepper. Cover with aluminum foil. Roast in lower third of 350°F (175°C) oven with brisket 55 minutes. Uncover; continue roasting 10 to 15 minutes or until vegetables are tender and begin to brown. Remove brisket from roasting pan and carve diagonally across the grain into thin slices. Serve with roasted vegetables and Lemon-Mustard Sauce. Lemon-Mustard Sauce: Heat oil in small saucepan over medium heat. Add shallot; cook and stir about 2 minutes or until tender. Remove from heat; cool 1 minute. Stir in sour cream, mustard, lemon juice, dill and honey. Season with salt and pepper. Cover; set aside