6445 Wilcrest, just south of Harwin
This is one of my favorite cheap eats places in Southwest Houston. I understand they've moved into a new, larger location in the last year or so but I've only been going about 9 months. It's not really very close to me or I'd probably go more often.
There's grab-and-go stuff at the cash register, a better selection earlier in the day, shelves of groceries and pharmaceuticals, etc., a small eating area that is frequently packed (mostly Asian customers) and a steam table offering plate lunches and a small selection of vegetarian diem sum.
You get a plate lunch for $5.50/$6.00 including a rice or noodle main dish and sides. It's enough for 2 meals for me and I'd never be able to finish it all so I've just gotten things to go. Everything is very tasty. I picked up a quart of the veggie soup one time, canh chua, which had mushroom pieces, greens, tomatoes and the most blazingly hot chillies I've ever put in my mouth.
I usually get a few pieces of the diem sum, too.
Prices and dishes may vary at the restaurant. Note the limited hours.