Also, how do you blacken them to get the skin off? I got an electric stove, so I have to broil them for a minute, but when I go to stuff them, they always fall apart.
Broiling them in the oven is death; as you have discovered, they'll be too mushy to work properly.
If you've got gas burners, turn the burners up to high and put the chiles on there and turn them with tongs. When they're blackened, take them off, put them in a plastic bag and throw them in the freezer for 15 minutes. The skin will peel off easily after that.
I've also peeled them by cooking them in oil first until the skin blisters. This yields a great chile, but it's a bit of a pain, because you have to figure out how to deal with a quart (or more) or peanut oil.
I'm sentenced to the hell of an all-electric kitchen, so I try to blister the chiles on the electic burners and finish them off with a kitchen torch. Sometimes I win and sometimes I lose. If you've got a gas grill that will let you get close to the burners, that can work, too.
Depending on the quality of the chile, sometimes you can rescue things by putting the chiles in the freezer until they firm up somewhat. Then you can stuff them and put them back in the freezer for a while before you batter them.
And if everything fails, you can still have a nice meal by building a layered casserole with the chiles laid flat on top of your filling and topped with beaten eggs and then baked. It's not the same as a genuine chile relleno, obviously, but after a few beers, it's still pretty damn good. The tangy taste of a good poblano is really enjoyable.
