We corresponded off-line on this one, but to spread the word to others, here are some suggestions:
- leftover rice, potatoes, or other carbs including gluten-free pasta you had at another meal
- tortillas (corn)
- gluten-free crackers or pretzels that are available at stores or at
http://glutensolution.com or other gluten-free site
- gluten-free cereals
- beans