Pad See Ew from Vieng Thai in Spring Branch

Hi guys! I grew up and spent most of my life in Houston but left the country four years ago. My absolute favorite meal anywhere in Houston was the pad see ew worth tofu from Vieng Thai. I've tried the same dish in plenty of other restaurants both in the States and in my new country, and no one does it the same. It's something about the sauce I think. It has a hint of sweetness that I haven't found anywhere else. If anyone has any idea what they could be doing differently (or convince the restaurant to disclose the recipe!) I'd my appreciate it. I'm going to post this in r/askculinary as well, and try my luck. Thanks!