Season the tuna with salt and a little of the sunflower oil, pickled ramps and a few of the Szechuan peppercorns to taste, making sure to double check the seasoning before you plate the dish.
On the middle of a chilled plate, place the tablespoons of the lemon aioli, then put a small ring mold down and pack the tuna mixture into it, pressing down lightly with a spoon to make it stay put.
Garnish with some of the kinome leaves and a rice cracker, then serve immediately.
Notes
At the restaurant, I make this dish with an aioli made from whole, cooked lemons that are pureed and mixed with mayonnaise. You can just season some mayonnaise with fresh lemon or meyer lemon juice and zest to get a similar flavor.