01 -
Preheat oven to 350°F (175°C).
02 -
Flatten chicken breasts to 1/2 inch thickness using a meat mallet, or slice horizontally if particularly large.
03 -
Season both sides of chicken with kosher salt and black pepper. Lightly dust each side with all-purpose flour.
04 -
Heat olive oil and butter in an oven-safe skillet over medium-high heat. Sear chicken breasts for 1–2 minutes per side until lightly browned.
05 -
Remove skillet from heat. Brush each chicken breast with Dijon mustard, then top each with 2 slices deli ham.
06 -
Place skillet in oven and bake for 15 minutes.
07 -
Remove skillet from oven and top each portion with 2 slices Swiss cheese. Return to oven and bake for another 5 minutes, or until cheese is melted.
08 -
Serve immediately while hot.