Preheat your oven to 180 C (350 F). Lightly grease a 9x13 baking dish with butter, set aside. Pat the chicken dry with paper towels.
In a shallow dish, whisk together the mustard, mayo, and milk. In another shallow dish, mix together 2/3 the cheese and bread crumbs. Photo shows my cluttered counter, the cheese and bread crumb mix, the milk mix, and the greased baking dish. Set everything up like an assembly line to make this go very fast. And for those paying attention, I did swap the order of the plates, milk mix, breadcrumbs, then the baking dish.
Take each chicken breast and coat both sides in the milk mix, then coat in the bread crumbs mix, place in the baking dish.
Pour the remaining mustard and milk mixture over the chicken.
Then sprinkle on the remaining cheese. Add black pepper if desired.
Bake for 30 to 45 minutes until cooked through, cut one breast in half to check. Serve. On pasta is great with some of the sauce spooned over the pasta, and a vegetable on the side would make this a complete meal.
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