Mix together, soy sauce, water, garlic and lemon juice.
Add the chicken and pork.
Cover tightly and marinate overnight.
Roast the chicken and the pork together in a 350 degree oven until done.
The chicken takes about an hour.
The pork takes about an hour and a half.
When cool, cut into matchstick pieces.
In a wok, or dee-sided frying pan, warm the oil.
Over medium heat, add the celery, cabbage, onions and mushrooms.
Stir fry until celery and onions are tender.
Add chicken and pork.
Stir until heated through.
Add soy sauce, salt and pepper to taste.
Remove this mixture from heat.
Stir in bean sprouts.
When working with egg roll wrappers be sure to cover them with a damp cloth to prevent them from drying out.
To fill each roll, mound about 2 heaping tb of filling just below the center of the egg roll.
Fold bottom corner up over filling to cover, then fold in the two outside corners.
Roll closed, sealing shut with a bit of egg white.
Put oil in a wok or large pan to a depth of about 2 inches - deep enough to cover the egg rolls.
Over medium-high heat, warm the oil and carefully add the egg rolls, one at a time.
Deep fry about 2-3 minutes, until golden brown on both sides, turning once.
May be kept warm in 200 degree oven until serving time.
Serve with dipping sauce.
DIPPING SAUCE: Combine soy sauce, mustard, garlic powder, vinegar and brown sugar.
NOTE: Egg rolls may be frozen after frying and cooled.
Reheat in oven to serve.