01 -
Heat a griddle on medium-high heat. Cook the poblano peppers until all sides are charred (about 15-20 minutes), turning every few minutes.
02 -
Seal the charred peppers in a plastic bag, and let rest for about 15-20 minutes to loosen the skins.
03 -
Meanwhile, prepare the flour mixture. In a large shallow bowl, combine flour, salt, pepper, oregano, and garlic powder. Set aside.
04 -
Remove the chiles from the bag, and carefully peel the charred skin off.
05 -
Slice a vertical line down one side of each chile, starting from the stem down to the tip. Remove the seeds with a spoon or your hand (consider using disposable gloves).
06 -
Stuff each pepper with about ¼ cup of queso fresco, then 1 heaping tablespoon of diced onion, and ¼ cup of shredded mozzarella. Gently squeeze the seams together to close the peppers.
07 -
In a large bowl, add egg whites and use a handheld mixer to whip until fluffy and soft peaks have formed. Add the egg yolks and whisk until just combined.
08 -
Pre-heat a large skillet on medium-high heat, with about 1.5 inches of oil for frying.
09 -
Place a stuffed pepper in the bowl of flour-mixture. Rub and pat the flour mixture on the pepper until completely coated, keeping the seam closed.
10 -
Carefully dip the floured pepper into the egg-mixture, making sure to hold it closed the whole time. Once coated all around, lay it in the hot oil.
11 -
Fry the peppers until they are golden brown on both sides, about 3 minutes per side. You can fry about 3 at a time in a large pan.
12 -
Remove chiles rellenos from oil and drain on paper towels. Serve immediately while hot and crispy.