Brown beef in butter in skillet; add cabbage, celery, soy sauce, 2 tablespoons sugar, onions, bean sprouts and 1 teaspoon salt.
Cook for 5 minutes; drain.
Let stand until cool.
Sift 2 cups flour, remaining salt and cornstarch together.
Beat egg and 1 teaspoon sugar together; stir into dry ingredients.
Blend 2 cups water into mixture gradually; beat until batter is smooth.
Grease 6-inch skillet lightly with small amount of oil.
Pour about 4 tablespoons batter into pan; tilt pan to spread batter over entire surface.
Cook until edges pull away from side; gently turn with fingers.
Remove from pan; spoon about 1 table- spoon ground beef filling in center.
Fold edges to- gether.
Stir 1 tablespoon flour and 2 tablespoons water together.
Seal edges of rolls with flour mix- ture.
Fry rolls in deep fat until browned.
Spread sparingly with hot mustard to serve.
Yield: 30-40 egg rolls.