D. FLAVOR FOUNDATION
It’s hard to overstate the importance of this pungent condiment—most typically made from fermented anchovies— in Vietnamese food. Some brands are more flavorful than others: Look for Red Boat from Vietnam or Thai Megachef. It is used as a cooking ingredient in these recipes, but fish sauce is also used as a table condiment in Vietnam. It’s not exactly traditional, but a dash can add a jolt of salty, savory flavor to your banh mi.