We're chile relleno hunters, and we've spent years seeking the perfect specimen. In our culinary travels, we've encountered numerous wanna-bes, from rellenos that required a chain saw to those that collapsed in an indigestible heap, like a baking pie in an artillery range. Splat. The unassuming little restaurante named Rosita's has the best we've come across north of the border: firm, but not too firm, liberally coated ? though not slathered ? in cheese, fluffy as a freshly groomed Pomeranian, tender as love's first blush. Rosita doesn't skimp on the fixings, and her prices are delectably low. On a recent visit, three of us ordered full meals ? plus a round of bottomless iced teas ? and walked out a mere $23 in the red. Our hats are off ? and our belts are loosened.