Steps
1. Prepare the tuna butter by finely mincing the smoked cured tuna and mixing it thoroughly with softened unsalted butter until creamy.
2. Toast the brioche slices lightly with a bit of butter until golden and crisp.
3. Spread the tuna butter generously on one side of each toasted brioche slice.
4. In a small bowl, combine mayonnaise, wasabi paste, and yuzu juice to create the wasabi-yuzu mayo.
5. Spread the wasabi-yuzu mayo over the tuna butter on one slice.
6. Layer the fresh thinly sliced tuna over the mayo.
7. Add a layer of pickled cucumbers for tang and crunch.
8. Spoon a thin layer of xnipec salsa over the cucumbers to add a spicy and citrusy brightness.
9. Close the sandwich with the second brioche slice, tuna butter side down.
10. Serve immediately and enjoy the complex flavors.