Combine first 6 ingredients (shallot through sriracha) and stir to combine. Add tuna and and avocado; gently stir to combine. Mound on a small serving plate or press into an oiled mold or small bowl and turn out onto serving plate for a more elegant presentation.
Finish with a drizzle of sriracha sauce on plate along with a drizzle of combined ponzu with mayonnaise. Garnish with microgreens if desired and serve with crackers or cucumber slices.
Video
Notes
K&L serves the tartare with pot sticker wrappers that have been brushed with buttermilk pressed into a mixture of black and white sesame seeds and deep fried @ 300 degrees until golden brown.
You can scale this recipe to serve as many as you like. Be sure to note the volume of your mold (if using) and use multiple serving plates or serve multiple stacks on a single plate.