Try Sam Woo in the back of Ranch 99 market.
They sell huge portions of B-grade food at the counter for $3.50. I mean huge – enough for 2. If I were homeless, I’d eat there every day and write a book “San Diego on $3.50 a day.” The book would be 1-page long and say “Eat at Sam Woo.”
The sit-down food is quite good but pricier than the take-out.