This combination tastes as good as it looks: claret-colored rare tuna set against its green coating, served with a yellow-orange salsa.
Make Ahead: The salsa needs to rest for at least 1 hour before serving so the flavors can meld. It can be refrigerated for up to 5 days. The seared tuna needs to be refrigerated for at least 30 minutes before the pistachio coating is applied. The coated, wrapped tuna needs to be refrigerated for several hours and up to overnight before serving.
- For the salsa
- 1 small (3 3/4 ounces) cucumber
- Flesh from 1 large, ripe papaya, cut into 1/2-inch dice (1 1/3 cups)
- Flesh from 1 large, ripe mango, cut into 1/2-inch dice (1 1/2 cups)
- 2 small red chile peppers, seeded, then finely chopped
- 1/2-inch piece peeled fresh ginger root, grated
- 1 small red onion, finely chopped
- Finely grated zest and juice of 2 limes
- 2 tablespoons fresh lemon juice
- 2 tablespoons Thai fish sauce
- 1/4 cup olive oil
- 2 tablespoons superfine sugar
- Kosher salt
- Freshly ground black pepper
- For the tuna
- One 2 1/4-pound piece tuna loin
- 2 tablespoons olive oil
- Coarse sea salt
- Freshly ground black pepper
- Scant 1 1/4 cups raw or roasted unsalted pistachios
- Finely grated zest of 1 lemon
- 5 tablespoons Dijon-style mustard
For the salsa: Peel the cucumber, if desired. Cut it in half lengthwise, then scoop out and discard the seeds. Cut it into 1/2-inch dice, transferring them to a serving bowl as you work. Add the papaya, mango, red chili peppers, ginger, red onion, lime zest and juice, lemon juice, fish sauce, oil and sugar. Toss to combine, then season with salt and pepper to taste. Cover and refrigerate until ready to serve.
For the tuna: Heat a grill pan or large cast-iron skillet over high heat.
Use a sharp knife to cut the tuna loin lengthwise, along natural divisions in the fish, into 2 or 3 cylindrical pieces. Brush them all over with the oil, then season with salt and pepper to taste. Add to the pan or skillet and sear on each side, for a total of no more than 3 or 4 minutes; the tuna should be rare at the center and just cooked on the edges (a 1/2-inch margin or so). Transfer to a plate and refrigerate until well chilled (about 30 minutes).
Chop the pistachios, preferably in a food processor, to the consistency of fine crumbs. Scatter them on a rimmed baking sheet and mix with the lemon zest.
Lay 2 or 3 good-size pieces of plastic wrap on the work surface.
Place a piece of seared tuna loin on one piece of plastic wrap. Brush with some of the mustard on the three visible sides, then invert and transfer to the pistachio-lemon mixture. Press gently to completely coat on the three sides. Brush the top with mustard, then invert to coat the fourth side, pressing gently so the mixture adheres. Transfer to a piece of plastic wrap; wrap tightly and refrigerate. Repeat with the remaining tuna pieces, mustard and coating. Chill for several hours and up to overnight. (Reserve/refrigerate the remaining pistachio mixture that didn't touch the fish, if desired, to use within a day.)
To serve, unwrap the tuna and cut it crosswise into 1/2-to-3/4-inch slices. Serve with the salsa on the side or on top.
Adapted from "Ottolenghi: The Cookbook," by Yotam Ottolenghi and Sami Tamimi (Ten Speed Press, 2013).
Tested by Bonnie S. Benwick.
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