Preheat broiler. Spray 10-inch oven-safe skillet with cooking spray; heat over medium-high heat.
Add beefaroni, drained tomatoes, ketchup, pickle and mustard to skillet. Heat 5 minutes or until hot, stirring occasionally.
Top with cheese. Lightly spray torn bun with cooking spray and place on top of cheese. Place skillet under broiler 2 to 3 minutes or until bun pieces are browned and crisp.
No hamburger bun on hand for the topping? Two slices of bread may be substituted. And dill pickle relish could be substituted for the chopped dill pickle. The beefaroni mixture could be served in hamburger buns, topped with American cheese for 'cheeseburger joes'. Get the kids involved with preparation by letting them add ingredients to the skillet and help stir the dish. They also could tear up the hamburger bun. To help give your family even more of the good stuff they need, you can use Whole Grain Beefaroni instead of Regular Beefaroni.