While visiting Ten-Ichi, tentsuyu—tempura dipping sauce—accompanied each order of tempura, along with a dish of sea salt, a lemon wedge, and curry powder. For tempura that includes shrimp, scallops, and/or kisu (Sillago sihama, a small white-fleshed fish), the chefs suggest seasoning with salt and lemon; for anago (fresh seawater eel) tempura, they recommend salt and curry powder. Ten-Ichi used a custom-blended oil to cook its tempura; we found a mixture of eight parts corn oil to one part Asian sesame oil to be a satisfactory approximation. Fresh seawater eel can be very difficult to find; ask your local Japenese restaurant for a possible source.
FOE THE DIPPING SAUCE:
1 6" piece kombu (dried sea kelp)
1 cup (about 1/2 oz.)
katsuobushi (dried, smoked bonito flakes)
1/4 cup mirin (sweet rice wine)
1/4 cup soy sauce
1/2 cup finely grated peeled daikon
FOR THE TEMPURA:
6 cups corn oil
3/4 cup Asian sesame oil
16 fresh ginkgo nuts, shelled and peeled,
or canned ginkgo nuts, drained and patted dry
8 snow peas, trimmed
1 1/4 cups cake flour
12 large shrimp, peeled with tail shells intact,
deveined, bellies deeply scored crosswise in 3 places,
and patted dry
1 2-oz. piece (about 12" long) skinless anago (fresh seawater eel) filet,
quartered crosswise and patted dry (optional)
4 skinless, boneless, headless, cleaned kisu or 1 5–6-oz. skinless
flounder filet, quartered crosswise; patted dry
4 shiitake mushrooms, stemmed
4 medium asparagus spears, trimmed of tough fibrous ends
1 small Japenese eggplant, trimmed, halved crosswise,
then lengthwise, with skin of each piece scored with an X
2 sea scallops, connective muscle removed and discarded,
scallops halved crosswise and patted dry
1. For the dipping sauce: Gently wipe any dirt off kombu with a damp cloth without removing the flavorful white powder. Put kombu and 4 cups cold water into a medium pot and bring to a gentle simmer over medium heat, about 10 minutes. Simmer kombu until soft, about 10 minutes more. Remove kombu and discard. Add bonito flakes to pot and simmer for 10 seconds without stirring. Remove pot from heat and set aside to let steep for 2 minutes. Strain stock (dashi) through a cheesecloth-lined sieve into a bowl.
2. Put 1 cup of the dashi into a small pot. Save remaining dashi to make sauce for tendon (see variation below), if you like, or for another use. Add mirin and soy sauce to dashi and bring to a boil over medium-high heat. Set dipping sauce aside to let cool to room temperature. Divide dipping sauce between 4 small bowls. Gently squeeze excess liquid from daikon, shape into 4 mounds, and place 1 mound in each bowl.
3. For the tempura: Put corn oil and sesame oil into a large flat-bottomed wok or a wide heavy pot and stir to combine. (The oil in the wok or pot should reach a depth of 2"–3"; add more of each oil to wok or pot in the ratio of 8 parts corn oil to 1 part sesame oil, if necessary.) Heat oil over medium-high heat until temperature registers 375°–390° on a candy thermometer.
4. Meanwhile, skewer 1 of the ginkgo nuts onto a wooden toothpick, fold 1 of the snow peas in half and skewer onto same toothpick, then slide another ginkgo nut onto toothpick next to snow pea. Repeat with remaining ginkgo nuts and snow peas to make 8 skewers in all. Set aside.
5. Put egg and 1 cup ice water into a medium bowl and gently whisk together until just combined and slightly foamy. Add one-third of the flour at a time to egg mixture, gently whisking in a cutting motion after each addition until barely combined. Take care not to overmix; batter should be lumpy with a ring of unmixed flour around the edge of the bowl. Set bowl with batter over another bowl filled with ice water to keep batter cool.
6. Working in 3 batches, dip all but tails of 4 of the shrimp into batter, then deep-fry, turning shrimp with a spider halfway through cooking time, until batter is crisp and shrimp are just cooked through, 1–1 1/2 minutes. Adjust heat to maintain temperature of oil between 375° and 390° and skim any excess batter floating in oil as you work. Transfer shrimp to a wire rack to let drain for 10–15 seconds.
7. Working in individual batches, dip eel (if using), kisu or flounder, ginkgo nut–snow pea skewers, gill side of shiitake mushrooms, asparagus, eggplant, and scallops into batter, then deep-fry, turning halfway through cooking time, until batter is crisp (eel, kisu or flounder, and ginkgo nut–snow pea skewers take 1 minute; shiitake mushrooms, 60–75 seconds; asparagus, 75–90 seconds; eggplants, about 2 minutes; and scallops, 1 minute at 385°). Cut asparagus in half crosswise on the bias. Transfer tempura to tempura paper– or paper towel–lined plates and serve with dipping sauce on the side. For the crispest tempura, serve individual tempura as soon as finished deep-frying, or serve assorted tempura together at once (see photo, facing page; clockwise from top right: shrimp, shiitake mushroom, ginkgo nut–snow pea skewers, asparagus, scallop, kisu, eel, and eggplant).
Variation—Ten-Ichi Tendon (Tempura on Rice): Tendon is served with a sauce similar to tentsuyu (the dipping sauce served with tempura; see recipe, above) but typically sweeter, more robust, and sometimes thicker—although the flavor and the texture of the sauce vary from restaurant to restaurant. At some establishments, tempura is arranged on top of the bowl of hot steamed rice, the tendon sauce then poured over it; others put the sauce between the rice and the tempura. Chef's at Ten-Ichi quickly dunk the tempura into the sauce, then lay the pieces atop the rice. To make the tendon sauce, put 3/4 cup of the reserved dashi, 1/4 cup mirin (sweet rice wine), and 1/4 cup soy sauce into a small pot and bring just to a boil over high heat. Keep hot over lowest heat. Divide 6 cups steamed short-grain rice between 4 deep bowls. Drizzle 1 tbsp. hot tendon sauce over each serving of rice. Quickly dunk hot tempura, one piece at a time, into tendon sauce, then arrange on top of rice. Serve at once. Serves 4.