Slice down the side of each chicken breast, making a pocket.
Place the haggis chunks into the pocket of each chicken breast.
Wrap each breast in bacon and secure with a toothpick if necessary.
Heat the oil and butter in a non-stick frying pan over a medium to high heat. Sear the bacon wrapped around the chicken breasts for 2 minutes on each side.
Place the bacon-wrapped chicken breasts on a baking tray and transfer to the oven for 35 to 40 minutes or until cooked through and piping hot.