Combine pork, spinach, garlic, scallions, salt, sherry & sesame oil and mix thoroughly. Place 1 spoonful filling in the center of each wonton wrapper. Brush inside edges of wrapper with beaten egg, bring all four corners to the center and press together, sealing the seams all the way down each side.
This makes about 50 wontons. Uncooked wontons can be wrapped and kept frozen for 1 - 2 weeks.
To cook for soup: Bring 3 quarts of water or stock to a boil and drop in the wontons. Do only as many at once as are not crowded in the kettle. Return to boiling, reduce heat and cook, uncovered, for 5 minutes. Lift out with slotted spoon and drain in colander. Bring the stock back to boiling, add more wontons and repeat as before. When ready to serve, place five wontons in each bowl, sprinkle them with a little soy sauce, then pour hot seasoned chicken stock over them. Garnish with stemmed fresh spinach leaves, and/or sliced green onion.
Fried wontons: Deep fry in vegetable oil until golden, and serve with sweet & sour sauce for dipping.