Place the chicken breasts in a medium saucepan (3-quarts is a good size). Cover with water with an inch or two of water, and bring to a boil. Boil them or until they are cooked through, 160 degrees at the thickest point. If the breasts are frozen, it will take 30-40 minutes. If they're fresh, it may take 15-20. Use a meat thermometer to be safe.
While the chicken is cooking, prepare bacon using your preferred method. We fry ours – put it in a dry pan, heat over medium heat, and cook until it's just beginning to get crispy. While it's cooking, fold a couple of paper towels on a plate. When you remove the bacon from the pan, lay them on the paper towel to draw away more of the fat.
When the chicken is done, shred it with two forks – use one to hold it and the other to shred the meat. Put the meat in a sauté pan, cover with BBQ sauce, and heat until the sauce is bubbly.
While the chicken is rewarming, toast your waffles. You can either do it 2 at a time in the toaster or you can place all 8 on a baking sheet in the oven.
Now you're ready to assemble your sandwiches – place a warm waffle on the plate, cover it with chicken, add a piece of cheese (so it melts atop the hot chicken), then a few slices of bacon, a leaf or two of lettuce, and a slice of tomato. Top with another waffle, and you have a hot and hearty sandwich, great for a quick dinner!