sweet and sour recipe

This is from the Mary Moore cookbook, and is actually called "Party Pork, Chinese Style."

Instead of 1 lb of cubed pork, dredged in 1/4 cup of flour, 1 1/2 tsp salt and 1/8tsp pepper, I make up a pile of little meatballs (a pack of lean hamburger).
I put the meatballs in a frying pan with the lid on to cook (med temp?) while I make the sauce.
Check the meatballs from time to time, and remember to turn them and drain the fat off.

Sauce:
1 cup celery, diced
1 green pepper, slivered
1 small onion, thinly sliced
1 19oz can of pinapple tidbits with juice
3/4 cup ketchup
1/2 cup brown sugar, packed
1 T prepared mustard
1 T Worcestershire sauce
1/4 c (approx) flour
salt & pepper to taste

Mix together, and pour over meatballs.
Stir, cover and simmer (stirring occasionally) for 30 minutes.
Serve over fluffy rice.