First of all, we need to soak the crystal powder in warm water 15 to about 20 minutes, and then control the moisture after soaking. Then chop sour beans and mustard tuber, chop lean pork, marinate with a little soy sauce, cooking wine and a spoonful of starch for about 5 minutes, and chop pepper, ginger, onion and garlic for later use. Then add Jiang Mo, minced garlic and pepper and stir-fry until the oil in the pan is hot. Add minced meat and stir-fry for about 2 minutes. Finally, add water to boil, and add sweet potato vermicelli after the soup boils, until the soup in the pot is almost completely absorbed by vermicelli. Season with chopped green onion and chicken essence, and it's done.