Preheat oven at 375 degrees F. Chop the bacon into fine pieces. Cut the tomatoes into small chunks. Mix the bacon, tomato, Miracle Whip, and cheddar cheese together, and set aside.
Separate the croissant rolls. Grease the cups of a muffin tin. Spread one roll per muffin cup to the outside of the edges to a make a crust. It should resemble a mini-quiche. Place the mixture in the crusts to two thirds full.
Bake for 10 minutes. Place on cooling rack for ten minutes. You can serve them warm, or cold after refrigeration for 1 hour.