Preparation
1. Roast the chiles*
Roast and peel each chile and let them cool. *If fresh chiles are unavailable, use canned whole green chiles.
2. Remove the seeds
Insert a sharp knife into the top of the chile, just under the stem and slice downward about half way down the chile. Using a spoon or a knife, scrape the seeds and the white membrane out, without tearing the chiles flesh.
3. Stuff the chiles
Place a slice of cheese into the chile, but don't force it. If the cheese is too large, trim it down until it fits inside. Make sure the open edges of the chile still come together.
4. Prepare the chiles
This step is optional Place half of the flour on the bottom of a plate. Place the chiles on the flour and sprinkle the rest of the flour on top. Use your finger to make sure the entire chile is coated. Dust off remaining flour and set chiles aside. If you rinsed your chiles in water, this step is important for the batter to stick.
5. Prepare batter
For a simple batter, whip 3-6 egg whites until stiff. Slowly fold in yolks and a pinch of salt. Or use your favorite batter recipe.
6. Cook chiles
One at a time, dip the stuffed chiles into the batter and then into the hot oil. Cook until batter is a crisp golden brown.
7. Drain excess oil
Remove chiles from the oil and drain on paper towels.
Tips:
1. Use cold eggs for the batter.
2. Test the oil with a drop of batter before putting a whole chile in. If the drop of batter sizzles and floats to the top, it's the right temp. If it sinks, the oil is not hot enough.
3. The flour should be a very light coat. It helps the batter stick to the chile.
4. Monterey Jack and Queso Blanco work well for Chile Rellenos