General Tso'S Chicken

1. Make the sauce by combining all the ingredients in a small bowl. Set aside.
2. To prepare the chicken, unfold the chicken thighs and lay them on a cutting board. Remove as much of the sinew as possible. (If some parts are very thick, cut them in half horizontally.) Slice a few shallow crosshatches into the meat. Cut each thigh into roughly 1/4 -inch slices and place in a large bowl. Add the soy sauces and egg yolk and mix well. Stir in the potato flour and 2 teaspoons peanut oil and set aside. Using scissors, snip the chilies into 3/4 -inch pieces, discarding the seeds. Set aside.
3. Pour 31/2 cups peanut oil into a large wok, or enough oil to rise 11/2 inches from the bottom. Set over high heat until the oil reaches 350 to 400 degrees. Add half the chicken and fry until crisp and deep gold, 3 to 4 minutes. Using a slotted spoon, transfer the chicken to a plate. Repeat with the second batch. Pour the oil into a heatproof container and wipe the wok clean.
4. Place the wok over high heat. Add 2 tablespoons peanut oil. When hot, add the chilies and stir-fry for a few seconds, until they just start to change color. Add the ginger and garlic and stir-fry for a few seconds longer, until fragrant. Add the sauce, stirring as it thickens. Return the chicken to the wok and stir vigorously to coat. Remove from the heat, stir in the sesame oil and top with scallions. Serve with rice. Serves 2 to 3. Adapted from "The Revolutionary Chinese Cookbook," by Fuchsia Dunlop.