Pound chicken breasts to about 1/2 inch thickness.
On one half of the chicken breast, place about 1/2 ounce grated cheese and half the bacon. Fold the other half over to cover the filling.
Cover the top sides with mustard, then coat with Panko. Flip and do the same on the other side. Press the crumbs into the mustard. Save about 1 t. of mustard for the sauce.
Heat oil in heat proof frying pan (cast iron) until shimmering. Carefully add the breasts and brown, about 3 minutes. Turn and brown the other side.
Place pan in 350 degree oven for about 15 minutes, or until the chicken is throughly cooked.
Remove from the oven. Place chicken on plate and cover loosely with foil. Over medium heat, add wine and stock to the pan and stir to dissolve any juices. Add reserved 1 t. mustard and the capers. Taste for salt and pepper. Stir until sauce reduces. Serve the breasts with sauce over half, the remainder on the plate.