Meatballs in a sweet sauce is a recurring theme in 1950s-1970s American cooking. It’s not that much stranger than barbeque sauce. On the other hand, using a sauce as a condiment is dramatically different than dropping the meat into a vat of the sauce.
From a box sold in San Antonio, Texas.
Sweet and Sour Beef Balls with Pineapple and Peppers
Mix 1 lb. ground beef, 1 egg, 1 T. cornstarch, 1 t. salt, 2 T. chopped onion, and a few grains of pepper.
Form 18 balls or more–brown in oil/drain.
To 1 T. oil., add 1 c. pineapple juice and cook over low heat a few minutes.
Add mixture of 3 T. cornstarch, 1 T. soy sauce, 3 T. vinegar, 6 T. water and 1/2 c. sugar–cook until juice thickens, stir constantly.
Add meat balls, 4 slices pineapple (cut in pieces), 3 large green peppers (each cut in 12-15 strips lengthwise).