Well, if cilantro's a part of your dish, lime classically works fantastic with it. If you're going to add cumin, perhaps you might want to pair it with coriander and just a hint of cinnamon. Given that you are working with bacon, broccoli, mushrooms, and leeks, perhaps you could, instead of cumin, and losing the cheese and the creme fraische, go in an east Asian direction. Blend together ginger, sesame oil, sriracha, a dash of sherry or rice wine, and a little bit of peanut butter to make a fantastic, flavorful sauce for your chicken.