I'd call this Vietnam's version of a roastbeef sandwich, but the beef isn't roasted, it's steamed -- usually in a banana leaf. Nonetheless, with the mayo and the spice provided by chilli peppers it reminds me of a roastbeef sandwich. Also included, Chinese chives, cucumber, pickled carrot and daikon, and cilantro. The beef is usually made with some flavour enhancers like onion, garlic, pepper, and salt. This kind of banh mi isn't as popular as the pork version banh mi cha lua, but it's just as good so if you see it for sale you better pick one up.