As per usual RecipeTinEats, this was a delicious one. However, I wasn't sure if it was the butter or mix of butter/cheese oil and chicken juices that the chicken was floating in after the bake.
My chicken breasts were bigger than the recipe, so I baked it for a total of 30 minutes.
The health rating score on Whisk (RIP) says its 7.0, so maybe it was mix oil/chicken juice. If this is the case, I'd give it another shot. Maybe less butter and more olive oil and seasoning.