Place 3 pieces of pancetta in the centre of a large square piece of foil.
Lay the chicken breast across the pancetta and slice across the middle of the breast creating a small pocket in the side of the chicken.
Mix together the butter, rosemary and chopped garlic and stuff this into the pocket you have just created.
Carefully wrap the pancetta around the chicken breasts ensuring the pocket is well covered.
Now, carefully bring the edges of the foil together to form a parcel, taking care not to disturb the chicken. Ensure the 'ceiling' of the foil parcel is raised up above the contents so steam can circulate. Pour a small amount of wine into the parcel pinch the edges of the foil together to seal.
Place the parcels on the low rack and cook at 170C for 30 minutes. After this time, remove the chicken and open the parcels (take great care as they will be full of steam) and pour all the juices in
Return the opened chicken to the low rack and cook for a further 10 minutes until the pancetta is crispy.
Add a small amount of cream to the juices and warm slowly on a low heat. Remove the chicken and slice, then pour warmed sauce across the chicken slices.