Bun Mee is a mini chain in SF with fine bánh mì. But in the context of an airport, where you’re technically trapped and your only other option is a pre-packaged salad with wilted lettuce for $22, it’s actually one of the more flavorful options you can get in the terminal (they also have a location in Terminal 1). The sandwiches have fillings like lemongrass pork and grilled tofu, and there are also pretty good rice bowls topped with kimchi, spicy mayo, and a fried egg.