Hollow out tomatoes. Place in 9" round cake pan to prevent tipping.

 

Combine hot Macaroni and Cheese, bacon and onion in medium bowl; fill tomatoes with mixture. Combine bread crumbs, cheese and butter in small bowl; sprinkle mixture evenly on top of each tomato.

 

Bake in preheated 350 degree F oven for 15 to 20 minutes or until cheese is melted.