Where I'm from, using pablanos for chile rellenos is blasphemy. (well maybe thats harsh, pablanos are great for stuffing, but just don't get the name "chile relleno") If you serve a dish called chile relleno, it damn well better be made of Numex type green chiles, often Big Jims because they are one of the bigger Numex types so they can fit more inside. I'd suggest looking through the Newmex types for one that is a little hotter and still has decent sized pods - beaglestorm seems to know a decent amount about these and may have a suggestion.
LOL when S.S. posted this, the first thing I thought of was that I should post a good relleno chile to use before the poblano gets recommended. Like Flame said, nothing wrong with Poblano's (I use them for rellenos that I am going to give my friends that don't eat hot chile) But a true relleno (at least what is used AZ,NM, West TX) is made with a Big Jim (medium heat). I would recommend the Heritage Big Jim that the New Mexico Chile Institute released last year. If you want something hotter use a Barker chile. I generally use the Barker more but they are quite a bit smaller than the Big Jims so it is a bit harder to stuff them.
Also, I consider a true relleno to just be stuffed with cheese. (Munster, asadero, white chedder) and seasoned only with salt. If you fill it with cumin, oregano, meat, potatoes, corn, etc. I think it really detracts from the whole point of a relleno… which is to enjoy the flavor and texture of the green chile.
Basically you roast and skin the chile. Make a slit near the top, reach in with a finger and pull the seed pod out (leaving the stem to hold on to) carefully. Cut a piece of cheese about the size of a cigar, slide it in the slit. Roll the chile in salted flour then dip it into a bowl of egg whites beaten to fluffy with a yolk or two folded in. Coat the chile evenly then pan fry (you dont need a lot of oil, I use just enough to cover the bottom of the pan) in a skillet with vegetable oil till golden brown. I fry one side, flip it over, then usually try to hold and balance the thin edge of the chile with the spatula to brown the edges. My wife eats them straight up, I prefer to roll them in a flour tortilla. Most restaurants serve them smothered in a fresh tomato, onion, chile reduction type sauce. That personal preference, I prefer them plain so as to enjoy the chile flavor.
If you do want to fill them with meat and the entire kitchen sink then the poblano would probably be a better choice as they are much easier to stuff with that type of filling.
