I recently started visiting a great little Vietnamese restaurant on the edge of the Galleria area. On Hillcroft just south of Westheimer, Vietnam Coast has great sandwiches (listed here as an appetizer, but almost a meal by itself); fantastic Pho; and a variety of seafood dishes.
The spring roles were okay, but the lemon grass shrimp and their popular beef dish (ask the waiter-- he'll know what you mean) are very good.
They have a special section for Unique Dishes. Unfortunately, I don't have any specific recommendations, but am sure you'll enjoy whatever you order.
You will have a great meal before you spend $20, and that includes a couple of beers.