My favorite sandwich in all of Houston is... the Garden Sammie at Local Foods!
It is full of Brussels sprouts, avocado spread, hummus, pickled onions, tomato and is on ciabatta... and has so much flavor and crunch that you don't feel like you were cheated by ordering the veggie sandwich
This restaurant is crisp and cool and family friendly... so for my birthday this week, this was the spot we went. There are several Houston locations, but we went to Upper Kirby.
They don't have a dedicated kids menu, but you can order grilled cheese or some simple sandwiches.
Parking can be tight, but it is free and spots open up regularly... but go a little early or late for easier parking.