Since the Cinnamon Snail launched, New Yorkers have lined up for the truck’s vegan offerings. Its crème-brûlée doughnuts and maple-mustard-tempeh sandwiches appealed to even the most die-hard carnivores, but what made the operation most special was the man at the heart of it: founder and chef Adam Sobel — who seemed thrilled to introduce people to his eclectic food while maintaing an always-sunny disposition.