- 6-8 green chiles, such as Hatch, green, or poblano
- 5 ripe tomatoes, cored
- 1/2 small white onion
- 1 clove garlic
- 1/2 jalapeno, stem and seeds removed
- 1 Tbsp olive oil
- Salt and freshly ground pepper
- 1 1/2 cups shredded Mexican queso fresco
- 1 Tbsp dried oregano
- 4 large egg whites, plus 1 yolk at room temperature
- Canola oil, for frying
- All-purpose flour, for dredging
Turn a gas burner on high. Place chiles on burner and cook, turning with tongs, until blackened all over. Alternately, preheat broiler on high. Place chiles on a rimmed baking sheet and broil until charred.
Transfer chiles to a medium bowl and cover with plastic wrap or place in a paper bag and close. Let stand 10 minutes. When cool enough to handle, remove blackened skins from chiles, trying not to tear chiles. Do not rinse. Using a paring knife, slice lengthwise down chile, cutting through only one layer. Open chile like a book and carefully pull out seeds and inner membranes. You may need to use a paring knife to loosen top of seedpod. Repeat with remaining chiles.
In a blender, add tomatoes, onion, garlic and jalapeno and blend until smooth. In a saucepan over medium-low heat, warm olive oil. Add puree, season with salt and pepper and cook, stirring occasionally, about 25 minutes.
In a small bowl, add cheese and oregano. Season with salt and pepper and mix to combine. Fill each chile with about 2 tablespoons cheese mixture. Fold in sides to cover filling, then thread toothpicks across seam to seal.
Beat egg whites with a mixer on high speed until soft peaks form. Add egg yolk and beat 3 more minutes.
Heat canola oil in a deep skillet over medium-high heat until a deep-fry thermometer registers 375 degrees.
In a shallow dish, add flour and season with salt and pepper. One at a time, coat stuffed chiles with flour. Holding each chile by the stem, lower it into egg batter to cover completely. Let any excess batter drip off. Add chiles to hot oil, 1 or 2 at a time; fry, flipping once with tongs, until golden, 1 to 2 minutes per side. Drain on paper towels. Place a fried chile on each plate and pour warm sauce over it. Serve immediately.