Preheat your oven to Gas7 / 220
Crush the garlic cloves using a garlic press onto a small plate
Add the butter to the crushed garlic and mash with a fork mixing together well
With a sharp knife, slice the chicken breast length wise on the thickest side. Do not slice all the way through but enough to make a deep pocket
Stuff each chicken breast with the garlic butter
lay out 2-3 slices of the pancetta and place a chicken breast in the middle. Wrap the pancetta round the chicken breast tucking the ends underneath. Wrap each chicken breast tightly in tin foil and Place on a baking tray. Do this with each chicken breast.
Place in the oven and cook for about 30-45mins depending on how thick your chicken breast are.