Preheat oven to 425°F.
Coat large rimmed baking sheet with nonstick
spray. Boil next 3 ingredients in saucepan until
reduced to generous 3/4 cup, stirring often,
about 7 minutes. Mix in 1 tablespoon mustard.
Generously brush corned
beef all over with glaze; place in center of
prepared sheet. Toss carrots and 1/4 cup glaze
in large bowl to coat; place around beef.
Sprinkle carrots with salt and pepper. Roast
until carrots are tender and beef is golden,
brushing occasionally with more glaze, about 35
minutes. Transfer to platter, garnish with
parsley, and serve with Dijon mustard.