specifically a nigiri, which is a type of sushi consisting of a slice of raw fish over pressed vinegared rice. The topping appears to be unagi, which is grilled eel, often glazed with a sweet soy-based sauce. This piece of nigiri is garnished with a drizzle of a dark, glossy sauce, likely to be unagi sauce, and sprinkled with small white sesame seeds. The eel has a caramelized exterior suggesting it has been grilled, which is typical for unagi. A thin strip of nori (seaweed) is wrapped around the middle, securing the eel to the rice.