3/4 pound highest-quality tuna, preferably loin
1 teaspoon kosher salt
1 to 2 medium shallots, finely diced (about 1/4 cup)
2 teaspoons capers, drained well and chopped
1/4-1/2 teaspoon crushed red pepper flakes
2 tablespoons toasted pine nuts
1/3 cup high quality extra virgin olive oil
Juice of 1 lemon (at least 3 tablespoons)
1/2 teaspoon Dijon mustard
Radishes or cucumbers
Place the tuna in the freezer for 10 minutes; this helps it firm up, which makes it easier to slice.
Freeze your platter for serving.
Thinly slice your radishes into very think disks.
Cut the tuna into roughly 1/8-inch thick slices. Spread onto an even layer on a cutting board. When complete cover tuna with plastic wrap. Using a rolling pin – gently roll out tuna so it is nice and thin. May also use the flat side of a meat pounder. Lay the radishes overlapping slightly on the platter. Then transfer the tuna to the platter, arranging the slices in 1 layer, a best as possible.
Sprinkle the tuna generously with the salt, then with the shallot, capers, red pepper flakes.
Combine the olive oil and lemon juice and mustard in a jar close the container and shake well until the vinaigrette is emulsified. Spoon the vinaigrette over the fish. Top with pine nuts and serve immediately.