I call this one pan Open Faced Chicken Cordon Bleu my "skinny" version of the classic. With ham, Swiss and dijon, it isn't breaded and fried, it gets baked!
Preheat oven to 350°F. Pound chicken breast to flatten to 1/2" or if large, slice horizontally. Season both sides with salt and pepper. Lightly dust each side with flour.
In a oven proof skillet over medium high heat add the olive oil and butter. Quickly pan sear the chicken on both sides until lightly browned, about 1-2 minutes each side. Turn off heat and brush each piece of chicken with divided mustard. Top each piece of chicken with divided sliced ham and bake for 15 minutes.
Remove from oven and top ham with Swiss cheese. Bake for another 5 minutes and serve immediately.
Video
Notes
1. If large chicken breasts, slice horizontally for 4 pieces of chicken about 1/2" thick.2. I often times pick up lunch meat sliced ham and it is super thin and small. I use 3-4 pieces or use 1 large slice from deli.3. I often times pick up lunch sliced cheese and it is super thin and small. I use 2-3 pieces or use 1 large slice from deli.