Mai's Viet Namese Restaurant near the corner of Fitzhugh and Bryan in Deep East Dallas is a splendid, inexpensive and very friendly restaurant. Everything is very fresh, the pho is delicious, the seafood hot pot is absurdly generous, the "clay pot" dishes are phenomenal, the staff is very friendly, and the prices are pretty low. It has a neighborhood feel, although the "neighborhood" extends from lofts south of downtown out to Lakewood and beyond -- sort of a neighborhood of intention, not a geographical one, but anyway lots of regulars. Bring your own beer or wine. The actual geographic neighborhood is really sketchy though, so go for lunch your first time, until you know your way around. No kidding. You can park in the pool hall lot next door, the "pool hall parking" signs notwithstanding. And there are cameras all over the place so you won't get jacked.
While you're at that corner go over to Jimmy's Grocery. They have an unbelievable selection of imported Italian groceries at great prices. Stock up on parmesan cheese, prosciutto and Italian wines, try some different kinds of salami, and GET SOME PORCHETTA!!! (Pronounced GET SOME PORKETTA!!!) It's a doubled-over pork loin rolled in porkbelly (uncured bacon) and roasted, lightly smoked IIRC. Oh God take me home now. This is the lunchmeat they serve in heaven. I like to make sandwiches with porchetta and mild provolone (also a bargain at Jimmy's) on the "ciabbattini" rolls from Whole Foods, no mayo salt or pepper. Lordy. I will say that the bread at Jimmy's is a disappointment. Oh well. The meatballs are famous but I prefer my own. I think they work the meat too much and I don't really like the resultant texture. I'm not that crazy about the sausage either but it's better than no sausage. Plus it comes in those big Sopranos-looking coils so there's that.
Since you're close to downtown, if it's Friday, Saturday or Sunday morning call Luna Tortilla Factory and order some flour tortillas. They're on the Woodall Rogers access road next to the original El Fenix. El Fenix invented the combination platter and they used to be open 7-24. They had to close for curfew dring WWII and they couldn't find a key to the front door. Anyway Luna has really good corn tortillas, they make their own masa fron corn that they keep in the big hopper out back, and on weekends they have these flour tortillas that are just unreal. Get some on Friday and make quesadillas for a weekend brunch. These tortillas really are almost too serious to use for fajitas. You might die. I think Luna's is actually on McKinney but it's so far down you can hardly tell.