Yassa

What it really is

A Mauritanian Senegambian-style dish of marinated fish or chicken with lemon and slowly cooked onions.

Preparation and ingredients vary by region and household.

Yassa is built around a sharp marinade and a generous quantity of softened onion. The protein is marinated with lemon and seasonings, then cooked with onions until the latter become tender and form much of the accompanying sauce. This page keeps the Mauritanian record within the wider Senegambian yassa family; it does not claim that the preparation is exclusive to one country. Fish and chicken are distinct versions and should be named separately on a menu. Rice is a common base for serving but is not the defining sauce itself. The amount of lemon, chilli and onion varies by cook. Identify the protein and describe the onion-and-citrus preparation, while checking whether stock or a seasoning paste introduces other ingredients. A menu should avoid implying that all yassa is either fish or chicken.

Onion is not only garnish: it softens in the pan and forms an important part of the sauce. The lemon marinade gives acidity, but its sharpness is balanced by the cooked onions. Keep rice separate in the menu description and name whether the serving uses fish or chicken.

The onions should be soft enough to form a sauce around the protein, while lemon keeps the finish sharp. State whether the plate uses fish or chicken and list rice separately if it is included.

How it's served

• Serve freshly prepared, with customary accompaniments where appropriate.
• Recipes, ingredients and portion sizes vary by household and restaurant.

How to write it on the menu

• Confirm ingredients and preparation with the kitchen before making allergen or dietary claims.