In a bowl, mix together the ground pork, chopped shallots, wood ears, shiitake, dried shrimps, carrot, garlic, ginger, a teaspoon of salt, a quarter teaspoon of pepper, the five-spice powder, oyster sauce and sesame seed oil.
In a small bowl, mix the flour and starch with two tablespoons of water until smooth. Pour into the ground pork and mix well.
Form the ground pork mixture into two-inch balls.
Heat enough cooking oil in a wok or frying pan to reach a depth of at least two inches.
Over medium-high heat, fry the meatballs in the hot oil until nicely browned and cooked through, about 8 minutes. Scoop out and set aside.
Pour off the cooking oil leaving only about two tablespoonfuls.
Reheat the oil. Stir fry the onion, carrot, bell pepper and celery with a little salt and pepper for a minute or two.
Add the meatballs to the vegetables. Pour in the sweet and sour sauce. Cook until the sauce is bubbly and the meatballs are glazed.
Serve the meatballs with sweet and sour sauce at once.