Transplanted early to Southern California, food writer Jim Fobel has tasted his way through more than his fair share of chiles rellenos, a popular restaurant dish that gets dragged mercilessly through sauces and batters not worthy of the poblano that belongs therein. Neither neat nor easy to prepare, the rich-flavored peppers, filled with melting cheese and coated with a soufflé-like batter, demand attention and patience. This is the careful version he has refined over the