Trim the chicken of as much fat and other unsavory bits as possible. Lightly pound the chicken to a thickness of no more than 1/2 inch. Make some shallow crosshatch cuts into each piece of chicken then slice the chicken into irregular 1/4-inch slices. Combine the soy sauce and egg yolks in a large bowl, add the chicken and stir to coat. Stir in the potato flour and 1 tablespoon peanut oil and set aside. Using scissors, cut the chiles in half and discard the seeds. Pour 2 cups peanut oil into a wok, or large saucepan and set over high heat. Bring the oil to a temperature of 375°F and fry the chicken in batches until golden brown and crisp 3 to 4 minutes per batch. Transfer the chicken to paper towels. Pour all of the hot oil into another pan or other heatproof container and wipe the wok/saucepan clean.