One 1-inch piece of fresh ginger, sliced 1/8 inch thick
Juice of 1 lemon
Juice of 1 orange
6 tablespoons bottled yuzu ponzu sauce
1/3 cup bottled yuzu juice or fresh lime juice
Vegetable oil, for frying
1 small package mung bean noodles
Toasted sesame oil, for drizzling
Pinch of salt
12 butter lettuce leaves
9 ounces sushi-grade ahi tuna, cut into twelve 1/3-inch-thick slices
12 paper-thin slices of jalapeño, soaked in ice water
Sriracha chili sauce, for garnishing
In a small nonreactive saucepan, combine the soy sauce, sugar, ginger, lemon juice, orange juice, yuzu ponzu sauce and yuzu juice. Bring to a simmer, stirring until the sugar is dissolved. Remove from the heat and let cool completely.
In a medium saucepan, heat 1 1/2 inches of vegetable oil to 350°. Add the noodles and fry for 30 seconds, turning once with a slotted spoon until puffed. Drain the noodles on paper towels. Drizzle the noodles with sesame oil and season with salt. Gently break the noodles into 1-inch pieces and mound 2 tablespoons on each lettuce leaf.
Arrange the tuna slices on a large dinner plate and pour 1/4 cup of the Yuzu Ponzu over the fish. Let stand for 1 minute, then turn the fish and let stand for 1 minute longer. Set a tuna slice on each lettuce leaf and drizzle 1/4 teaspoon of the sauce on each leaf. Garnish each piece of tuna with a slice of jalapeño, a drop of Sriracha and a cilantro sprig and serve at once.
The Yuzu Ponzu sauce can be refrigerated for up to 1 month.