Trim all excess fat and gristle from the chicken breasts, and then cut them into pieces that can be rolled up. If your pieces are thick and hard to roll, try pounding them flat with a mallet or hammer covered with aluminum foil. Place 1 or 2 half rounds of dried beef, or an appropriate amount of sliced ham on top of an uncooked chicken breast. Roll the chicken breast, until it encompasses the filling. Close with a toothpick, and place in an 8-inch by 10-inch baking dish that has been sprayed with cooking spray. Continue until you have used up all your chicken breasts and filling. now, make your gravy. Combine 1 pint of sour cream and a 10 3/4 oz. can condensed cream of mushroom soup. Stir until the two ingredients are completely blended. Pour the mushroom-sour cream gravy over the top of the individual chicken rolls that are in your baking dish. Spread the gravy as evenly as you can on top, and let it drizzle down to the bottom. Top your casserole with 5 or 6 slices of partially cooked bacon. If you choose, you may separate the slices of bacon into smaller pieces and place them on the top of the casserole. Bake slowly in an oven that has been preheated to 275 degrees. Check your chicken breasts occasionally while they are cooking, to make sure you don't cook them too long. Remove from the oven after about 2 1/2 hours (3 hours for larger chicken rolls). Serve immediately, and be prepared for compliments!