If you Google it, you get this...
Calories in Publix 6 Inch Chicken Tender Sub - Calories and Nutrition Facts
Sometimes I just take foods and Google them; at least it gives me an estimate/starting point if I can't find the whole thing. Chinese/Vietnamese food is hard because there is so much variation, but something is better than nothing.
Previously, I would use the excuse of not finding a food to stop logging for the day. Bad idea!