When fresh, poblanos have a wonderful, somewhat sweet heat that makes a terrific vessel for rich-tasting butternut squash stuffing. Accompanied by corn tortillas or rice and beans, this makes a special vegetarian entree. Most of the preparation can be done in advance and the recipe can easily be doubled. Look for dark green poblanos about 5 inches long, with broad shoulders at the stem, tapering to a pointy tip. Wash your hands thoroughly after removing the seeds or wear rubber gloves; most of the chile oils are found in the seeds and connective membranes.