Ingredients: - 1 yellowtail fillet - 1/4 cup soy sauce - 2 tablespoons fresh lemon juice - 1 tablespoon rice vinegar - 1 tablespoon mirin - 1 teaspoon grated ginger - 1 green onion, thinly sliced Steps: 1. Slice the yellowtail fillet into thin sashimi slices. 2. Arrange the slices on a serving platter. 3. In a small bowl, whisk together the soy sauce, lemon juice, rice vinegar, mirin, ginger, and green onion. 4. Pour the ponzu sauce over the yellowtail slices. 5. Let the sashimi marinate in the sauce for about 10 minutes before serving. 6. Serve the hamachi sashimi with ponzu sauce as an appetizer or part of a sushi platter. Enjoy the fresh and delicate flavors of this hamachi sashimi with ponzu sauce!