Light and lacy tempura is one of the highlights of visiting a truly excellent Japanese restaurant. Much comes down to the treatment of the batter—keeping everything cold and working swiftly is key to slowing the gluten development in the batter, the culprit in a heavy, thick batter that absorbs too much oil. Low-protein flour such as cake flour is desirable, but the addition of cornstarch to all-purpose flour is remarkably effective in blocking gluten development.
As the batter warms up and is mixed around during the dredging process, the gluten develops further. To counter this, the batter is divided in two: One portion is refrigerated and used to coat the second half of the ingredients.
Serve this with soy-ginger dipping sauce and mushroom powders.
4 SERVINGS
EQUIPMENT: A 6-quart (6 l) cast-iron pot or an electric deep-fat fryer fitted with a basket; a deep-fry thermometer (optional); a wire skimmer; a pair of chopsticks; a tray lined with paper towels.
1-1/2 cups (220 g) cake flour (not self-rising), plus more for dredging
1/2 cup (65 g) cornstarch
1 bunch enoki mushrooms, dirty roots trimmed, clean roots still attached, rinsed, divided into 8 small bunches
8 medium, flat shiitake mushrooms, wiped clean with a paper towel
8 to 12 oyster mushrooms, wiped clean with a paper towel, any dirt from the underside removed with the tip of a sharp knife
7 ounces (200 g) monkfish or other firm-fleshed white fish, cut into 1-1/2 × 2-inch (3 × 5 cm) pieces
4 ultra-fresh sea scallops, without roe
4 large shrimp, peeled and deveined but tail attached (reserve the heads and shells for Shellfish Stock, or another use)
2 small cleaned squid, bodies cut into 1 × 2-inch (2.5 × 5 cm) strips or sliced into 1/2-inch (1.25 cm) rings, as preferred, tentacles halved
2 quarts (2 l) vegetable oil, such as sunflower oil
2 egg yolks, free-range and organic, chilled
2 cups ice water, plus 1/4 cup extra for thinning the batter, if necessary
1/4 cup (60 ml) toasted sesame oil
8 fresh shiso leaves
Fine sea salt or Dried Cèpe or Morel Salt, for dipping
1. Sift the flour and cornstarch together, or mix together in a bowl with a whisk, and place in the refrigerator to chill.
2. Prepare the mushrooms, fish, and shellfish in advance, making sure that they are all dry. Pat dry with paper towels, if necessary. Set aside on a tray at room temperature.
3. Pour the vegetable oil into the pot or deep-fat fryer to a depth of at least 2 inches (5 cm). If using a deep-fry thermometer to take the temperature of the oil, attach it to the side of the pot. Heat the oil over medium heat to 375°F (190°C), or until a wooden chopstick inserted into the oil begins to fizz with bubbles. Do not be tempted to use too high a heat to bring the oil to temperature, as it will be harder to control and keep stable once you arrive at your goal temperature.
4. While the oil is heating, place one of the egg yolks in a large bowl. Add the ice water and, using the chopsticks, mix together roughly. Add the sifted flour mixture and, again with the chopsticks, roughly mix together, six to ten strokes. The ingredients should not be well incorporated; there should remain a fair amount of unmixed flour. Divide the batter evenly between two bowls. Cover one of the bowls with plastic wrap and refrigerate.
5. Just before you begin to fry, add the sesame oil to the hot vegetable oil. Working quickly with half the mushrooms, seafood, and shiso leaves, as you want the batter to remain as cold as possible to prevent gluten development, dredge four or five pieces in the extra flour, then, using the chopsticks, dip each quickly in the tempura batter, making sure that each piece is fully covered in batter (no need to dredge the shiso leaves in flour, they can be dipped directly into the batter). Drop the pieces into the hot oil and deep-fry until golden, 3 to 4 minutes. Using the wire skimmer, transfer the tempura to the paper-towel-lined tray to drain.
6. Using the skimmer, skim away any drops of batter that remain in the oil. Let the oil come back to temperature before continuing with four or five more pieces. Repeat until you have fried the remaining half of mushrooms, seafood, and shiso leaves, thinning the batter with the extra ice water as necessary.
7. Take the second batch of batter from the refrigerator and repeat the process to cook the remaining ingredients. This will make sure the second batch is just as lightly crisp as the first.
8. Serve with the dipping sauce, powders, and salt, dipping the tempura first in the sauce and then in one of the dipping powders or salt.