The Vietnamese banh mi offers everything you’d ever want in a sandwich. It is an explosion of flavors and textures: tangy, crunchy, spicy, and savory. Chef Tebi Nguyen creates this culinary alchemy in an East Austin trailer: He takes pork that’s been marinated in fish sauce, garlic, red shallots, and a touch of honey and pan-sears it, then applies a final char with a blast of a torch. The meat is tucked into a baguette that’s been swiped with mayonnaise, and then showered with a crunchy tangle of cucumbers, jalapeños, and daikon.