In a medium bowl, combine the yuzu juice, ponzu sauce, filtered water, a pinch of sugar, and a teaspoon of sesame oil. Add a smashed garlic clove and whisk until dissolved.

Using a sharp knife, slice the sushi-grade hamachi thinly into approximately ¼-inch pieces. Arrange on a chilled plate.

Generously drizzle the yuzu ponzu sauce over the arranged hamachi slices.

Sprinkle finely sliced shallots, fresh cilantro, and serrano pepper over the hamachi. Zest a lemon on top and finish with flaky salt.

Serve immediately for the freshest taste, optionally with sushi rice or a cucumber salad.