Pho is a type of Vietnamese soup that can consist of various ingredients, but most versions of the dish include a dark broth made from beef stock, star anise, onion, cinnamon, cloves, fish sauce, and hoisin sauce. The contents of the soup may include bean sprouts, rice noodles, lime, beef, basil, and very hot peppers. Some pho restaurants choose to serve most of the ingredients as a side, allowing the person eating the dish to add the contents as he or she wishes. Pho is usually served as an entree, as it can be quite hearty when filled with enough contents.
The soup is usually prepared and simmered for a fair amount of time to allow the flavors to steep. Beef flank is then added to the broth, either already cooked or raw, to be cooked in the broth. Some pho restaurants choose to serve the dish just like this, without adding additional ingredients; other restaurants may add rice noodles before serving. The bowl of the soup is served alongside a tray of additional ingredients so the diner can add what he or she wants. Many restaurants also serve additional sauces, such as hoisin sauce, fish sauce, soy sauce, sriracha sauce, or chili garlic sauce. The soup can be quite spicy or mild depending on the diner's tastes.
Several variations of the dish exist. The most popular dish features beef flank, and another popular version features both beef flank and meatballs. Less common are chicken and vegetarian pho, though they do exist and may be served at some Vietnamese restaurants. Some versions of the soup are served with various seafood as well, such as shrimp or scallops. Most versions of the soup focus on beef, however, as various parts of the cow are used for flavoring. Beef tripe, tendon, and muscle are all potential meats used in various recipes. Some versions of the soup tend to be sweeter, while others tend to be spicy; the difference is usually apparent by region.
The origin of pho is not known, though many speculate it originated in Vietnam during the early twentieth century. Before this time, beef was not usually used in Vietnamese cuisine, as cows were primarily used for farming rather than eating. When the French were a major presence in the area, Vietnamese people began using beef in more dishes. Many people believe pho is a combination of French and Vietnamese cuisine, and speculation has arisen that the name pho may even have a French origin.