Preparation
Preheat oven to 205 °C (400 °F).
Butterfly the chicken breasts by cutting it lengthwise down the side without cutting all the way through.
Stuff each chicken breast with the slice of prosciutto, the cheddar and basil. Salt and pepper.
Heat oil in an ovenproof skillet on medium-high heat. Brown chicken breasts for 1 to 2 minutes on each side. Set aside in a dish.
In the same skillet, cook the shallots for 1 minute.
Add honey and cook for 30 to 40 seconds, until amber in colour. Add the vinegar, the mustard and the beef stock. Bring to a boil. Salt and pepper.
Add chicken breasts in the skillet and cook for another 12 to 15 minutes in the oven, until no longer pink inside.
If the sauce is too liquid, place skillet on the stove and allow to thicken for a couple of minutes on low heat.
