From New Flavors For Appetizers: Classic Recipes Redefined, Williams-Sonoma.
Matt says: I love tuna in any form — grilled, smoked, seared, raw in poke or carpaccio ––so this was the first recipe I made from the book. The fennel and radishes deliver that contrasting crunch. It’s heaven.
1 lb sushi-grade ahi tuna, well chilled
1 large or 2 small bulbs of fennel
1 bunch (about eight) radishes
1/4 cup fresh lemon juice
1/2 cup peppery extra-virgin olive oil
Sea salt and freshly ground pepper
Leave the tuna in the refrigerator until you are ready to cut it. If it is well chilled, it will be easier to work with.
If the fennel stalks are still attached, trim them and reserve for another use or discard. Reserve a few of the feather fronds for garnish, if desired. Remove and discard the outer layer of the fennel bulb if it is tough, or cut away any discolored areas. Halve the bulb lengthwise and trim the base of the core. Trim off the leafy tops and the root ends from the radishes. Using a mandoline or large sharp knife, cut the fennel bulb halves and then the radishes into paper-thin slices.
Using a long, sharp knife, and cutting with the grain, cut the tuna into 1/2-inch dice, removing any sinew.
Divide the fennel and radishes evenly among chilled bowls or plates. If desired, roughly chop some of the fennel fronds and add a few to each bowl. Arrange the tuna on top of the vegetables, again dividing evenly. In a small bowl, whisk together the lemon juice and oil until blended. Drizzle the lemon-oil mixture evenly over the tuna and vegetables and season lightly with salt and pepper. Serve right away.
Makes 8 servings.