I never thought that I would be stringing together the words “mild” and “chile” in the same sentence. And, no, I am not referring to some wimpy green bell pepper. I mean jalapeños, baby, and maybe habaneros or serranos, or any kind of chile that you speak of in hushed tones with a trace of trembling fear in some back room with the lights on. You can and will conquer chiles with a little help of Mexican crema, a tangy sauce that is closer to crème fraîche than to sour cream. It is the sauce that gives that cool creamy edge to Baja-style fish tacos and enchiladas and other dishes that call for a touch of dairy.