Preheat oven to 350 degrees F. Place bread on baking sheet sprayed with no stick cooking spray. Cut an oval or elongated football shape on top of bread and remove bread center to make room for the dip. Tear removed bread top and bread center into bite-size pieces. Set aside for serving.
Heat oil in large skillet on medium-high heat. Add vegetables; cook and stir 3 minutes or until tender-crisp. Stir Gravy Mix, cheese sauce, milk and roast beef into skillet until well blended. Spoon dip into bread.
Bake 15 minutes or until heated through. Serve dip with bread pieces. Drizzle with additional cheese sauce, if desired.
