A California roll is a type of sushi roll that is typically made with cooked crab meat, avocado, and cucumber. The ingredients are typically rolled up in a sheet of seaweed, known as nori, and then sliced into individual pieces. California rolls are often served with soy sauce for dipping, and may also be garnished with sesame seeds or green onions.

The dish is thought to have originated in the United States, specifically in the state of California, in the early 1970s. It is believed that the California roll was created as a way to introduce sushi to American palates, which were not accustomed to eating raw fish. By using cooked crab meat and avocado, the dish was made more approachable and flavorful for those who were hesitant to try sushi.

California rolls have become a popular menu item at many sushi restaurants, and are often offered as a starter or an option for those who are new to sushi. They are also frequently included in sushi platters or bento boxes, and can be found at many grocery stores and convenience stores.

In addition to the traditional version made with crab meat, avocado, and cucumber, there are many variations of the California roll. Some versions may include additional ingredients such as lettuce, shrimp, or mango, and some may be served with a spicy sauce or mayonnaise-based sauce. Some sushi chefs may also experiment with different types of fillings, such as tuna or salmon, or may use different types of wrappers, such as soy paper or rice paper, in place of nori.

Despite its name, the California roll is not a traditional Japanese dish, and is often considered by purists to be a form of Westernized sushi. However, it remains a popular and delicious option for those who enjoy sushi, and continues to be a staple at many sushi restaurants around the world.