Noodle soups are the backbone of street food and the best one I had was on the island of Phu Quoc in a dilapidated roadside stand with tiny plastic chairs. Bryan Caswell, who is about 6-foot-2 and stout as Texas, looked like a giant at a Hobbit’s tea party. The broth, like in pho, is the most important component of the dish. Here it starts with a base of dried shrimp and tomato, which is then simmered with pork trotters and aromatics like clove and lemongrass. It’s served with rice noodles, roast pork, trotters, Thai basil, a chewy fish-cake-like sausage and fresh sliced tomatoes. The fresh, tart tomatoes, lightly poaching in the warm broth, were perfect against the richness of the fatty pork. And lunch with a six-pack of Saigon beer cost about $5.