For the Sherry Vinegar Granita: In a small stock pot over medium heat, combine vinegar and 250 grams water. Bring to a simmer. Add sugar and salt. Remove from heat and whisk until both sugar and salt are fully dissolved. Add gelatin. Whisk until fully incorporated. Pour mixture into a shallow, nonreactive container, and freeze overnight.

For the Mountain Rose Apple Juice: Using a juicer, juice apples. Strain juice through a coffee filter-lined chinois. Transfer to a blender and add salt and xanthan gum. Blend until salt is dissolved and xanthan gum is hydrated. The juice should be thickened and viscous. Transfer to a nonreactive container and refrigerate.

For the Kombu Oil: Heat oven to 350°F. In a stockpot over medium heat, blanch kombu until soft, approximately 3 to 5 minutes. Lay flat on a sheet tray, and roast until crispy and dried. Transfer kombu to a blender. Add oil and salt. Blend on high 5 minutes. Strain mixture through a coffee-filter lined chinois. Transfer to a nonreactive container and refrigerate.

For the Winter Radish Salad: Using a mandolin, thinly slice 8 grams of each radish. Transfer to a bowl of salted ice water and let soak 5 minutes. Remove from water and pat dry with paper towels. Transfer to a bowl and season with olive oil and salt. Set aside.

For the Tuna Tartare: In a small bowl, combine tuna and oil. Season with salt. Toss to coat. Set aside.

To Assemble and Serve: Remove Sherry Vinegar Granita from the freezer. Transfer Tuna Tartare to a medium-sized, deep serving bowl. Pour Mountain Rose Apple Juice into the bowl until it reaches approximately halfway up the tuna. Cover the Tuna Tartare with the Winter Radish Salad, carefully placing the radishes all in the same direction. Drizzle a spoonful of Kombu Oil into the Mountain Rose Apple Juice. Garnish Winter Radish Salad with shiso. Cover the Winter Radish Salad with Sherry Vinegar Granita, making sure to keep the Granita on top and not let it fall into the juice.