Prepare the Fish: Using a sharp knife, slice the hamachi into thin, bite-sized pieces, approximately 1/4 inch thick. Arrange the slices in a circular or overlapping pattern on a chilled plate.
Make the Dressing: In a small bowl, combine olive oil, lime or lemon juice, sea salt, and freshly cracked black pepper. Whisk until well blended.
Drizzle and Season: Drizzle the olive oil and citrus mixture evenly over the sliced hamachi. Be careful not to drown the fish lightly coat it.
Garnish: Add optional garnishes, such as chili pepper slices, microgreens, or edible flowers. You can also add thin avocado slices and radishes for additional texture.
Serve: Serve immediately, or chill for 5-10 minutes to enhance the flavors. If desired, drizzle with ponzu sauce for extra flavor.