Hi all, I bought these Check breast stuffed with bacon balls from butcher & am not sure how to cook them evenly, any assistance please?

Ask the butcher.

I'm assuming if the bacon is inside the chicken it is not meant to get crisp. So I would probably braise it or bake at a really low temp (like 250/275) for several hours to keep everything moist while making sure the bacon gets fully cooked. I would also add something absorbent like hearty greens or diced potatoes to catch all the bacon goodness as it renders.