Meat and potatoes

Classic Midwest staple, a good filling hearty meal that everyone loves. My father is no exception to the rule, and this should in turn make cooking for him easy one would assume. In reality though it can be quite the opposite. My father will not eat a single green vegetable, or anything with so much as a little black pepper or other spice on it.  I am often stuck trying to cook a whole separate meal when I want to make something ethnic or healthy, and watch him eat French fries and macaroni and cheese. I would love some help and input on this topic, what do you think I can cook for a guy who will only eat like a five year old?