With three 14 year olds, my suggestion would be to try Grand China Buffet on Hawthorne in Torrance. They could choose whatever they personally like and there is a limited choice of dim sum (not of the best quality) but the variety is endless for other things. Plus, lunch is pretty reasonable.
Ocean Seafood in Chinatown is only a 20 minute ride from the south bay on a sunday, but if you drive just a little farther to SGV and Sea Harbour you can't do better.
3939 Rosemead Blvd
Rosemead, CA 91770
Now if it's ramen you wanted that's another story....