Saute your chicken, mushrooms and bacon in butter. When your chicken is browned on one side, flip it, along with the mushrooms and bacon. When the 2nd side of your chicken is starting to brown, put the swiss cheese and parmesan on top and cover for 1 minute. Uncover and place the bacon and mushrooms in a paper towel to soak up the grease. Saute your red onion quickly while your bacon and mushrooms are drying. Place your chicken over a bed of spinach, salt and pepper to taste. Top with dried bacon, mushrooms, red onion and diced tomatoes. Either squeeze the mustard in a zig zag pattern on top or put off to the side for dipping. Enjoy!