Pull head and tentacles away from body of squid. Cut tentacles away from head and discard head and insides. Peel off and discard skin from body. Peel skin off tentacles. Parboil 2 minutes and chop tentacles.
Place bean curds in a cheesecloth, squeeze out water, and smash into small pieces. Remove seeds from peppers and mince finely along with onion.
Blanch bean sprouts in boiling water and squeeze out water. Cut several times.
Mix chopped, cooked tentacles, bean curd, onion, peppers, bean sprouts, beaten egg and ground beef in large bowl, season with minced green onion, minced garlic, pepper and salt, and blend thoroughly.
Put filling into body of squid, making sure not to over stuff. Close off by making stitches. Place stuffed squid in preheated steamer and steam for about 15-20 minutes. Cool and cut into 1/2-inch-thick rings.
Meanwhile; mix vinegar, soy sauce, sugar and pine nut powder to make a sauce. Serve with the cooked squid.