Stem the mushrooms, then tear or cut the caps into pieces about 1/2-inch wide. Remove the strings and leaves from the celery and cut the stalks into 1/2-inch lengths. Combine the ginger and garlic in a small bowl. Cut the green parts off the scallions, chop them into 1/4-inch pieces, and save as a garnish. Cut the white parts of the scallions into 1/4-inch rounds and add them to the ginger and garlic. Place the chilies in a sieve, rinse, and shake them dry.
Mix the sauce ingredients together in a small bowl or measuring cup, adding the sweet soy sauce (or soy sauce plus sugar) to taste.
Place a wok over medium heat and pour in the oil when the wok is hot. Swirl the oil around and add the Sichuan peppercorns. When the peppercorns have toasted to a very dark brown, use a slotted spoon to remove and discard them. Turn up the heat under the wok to high. Add the chilies to the oil, fry them until they start to brown, and add the ginger, garlic, and whites of the green onions. Stir-fry these for a few minutes to release their fragrance.
Add the mushrooms and stir-fry them until they start to brown, and then add the celery and toss it with the mushrooms. Fry only until the raw edge of the celery is gone. Scoot the vegetables up the side of the wok. Add whatever protein you are using and fry them quickly in the oil at the bottom of the wok until they barely brown, adding more oil as needed to keep them from sticking to the wok. Toss them with the vegetables, and then pour the sauce around the edge so that it heats up quickly. Toss everything together quickly until the sauce thickens and forms a sheen over all of the ingredients. Taste and adjust the seasoning. Toss in the onion greens and peanuts and then serve immediately.
Sorry to be a pest, Is this sauce called "Lychee flavor Sauce" because Lychees are often included in the sauce or because it is used to flavor dishes with lychees or?
You're not a pest! It's more of a description of the fruitiness of the sauce itself. Lots of rich flavors popping in the background.