Yassa is a West African dish made of either chicken or fish that has been seasoned with lemon juice, spices, and plenty of onions. Basic yassas are simple to prepare, and require only a few ingredients. Cooks with more resources at their disposal often augment standard yassa with a variety of other vegetables and flavors. The dish is almost always served over rice.
Most food researchers believe that yassas first developed in Senegal, a country on the Western coast of Africa. Nearly all countries and cultures in this region have some version of yassa that they claim as their own, however. Yassa’s basic ingredients make the dish approachable and easy to prepare, without requiring any particular skill or expensive components. It is very much a “common” food, but is nonetheless regaled as something of a regional icon. Senegalese and West African restaurants throughout the world often feature yassas prominently on their menus.
There are two main ways of preparing the dish: one with chicken or small fowl, called poulet yassa, and the other with fish, called poisson yassa. The most authentic preparations call for the meat to be fresh caught and killed, then marinated in lemon juice. Meat from many wild West African creatures is particularly tough, especially the birds. Marinating in acidic liquids like lemon juice often helps speed muscle breakdown, softening the meat and making it more palatable. Most yassa chicken dishes require marinating the meat at least overnight, though fish is usually best if left to sit for only a few hours.
Lemons and onions often grow well and wild throughout Senegal and its neighboring countries. This makes them good additions to yassas, as they are both easy to find and inexpensive. Yassas can be made with little more than sautéed onions and lemon-flavored meat over rice, usually with locally-available spices added in to taste. Mustard and mustard seed is often considered a staple flavoring.
Even with a minimalist approach to ingredients, yassas tend to be quite spicy. It is not uncommon for cooks to add dried chili peppers, cayenne powder, or other spicing agents to the meat as it marinates, resulting in spicy fish or spicy poultry right from the get-go. Adding dried seasonings like pepper flakes and grated herbs to the finished product is popular, too.
Serving these marinated dishes over rice helps substantiate them. Rice will soak up the juices from the meat and the onion, and helps the dish to stretch farther and feed more people. Families will often cook yassas as a dinner one night, but serve them incrementally over rice for a number of days.
Depending on where cooks are and what they have available to them, yassas can contain much more than just lemons and onions. Carrots, cabbage, and garlic are some of the most popular additional yassa ingredients. Sometimes these are braised and cooked along with the meat, but they can also be added raw, much as a garnish would be.