Heat oven to 375°F. Spray large skillet with nonstick cooking spray. Heat over medium-high heat until hot. Add ground beef and onion; cook and stir until beef is thoroughly cooked.
Meanwhile, in medium saucepan, bring water, butter and salt to a boil. Remove from heat. Stir in potato flakes and milk. Set aside.
To beef mixture, add gravy, chili sauce and vegetables; mix well. Bring to a boil. Spoon mixture into 4 (2-cup) individual ovenproof casseroles or bowls. Place casseroles in ungreased 15x10x1-inch baking pan.
Add egg to potatoes; mix well. Stir in cheese. Spoon or pipe potato mixture around edge of each casserole. Sprinkle with paprika.
Bake at 375°F. for 20 minutes or until potatoes are set.