Vegetable Tempura

When making tempura, you must be mindful not only of the temperature of the oil, but also that of the batter and vegetables. Use a deep-fryer thermometer to make sure the oil stays between 335°F (168°C) and 350°F (175°C) to prevent sogginess. Meanwhile, keep the batter cold to produce a lacy and light coating. Vegetables should be at room temperature to minimize the drop in oil temperature when frying.
Prep Time: 15 minutes

Cook Time: About 2 minutes per piece
Makes 4–6 appetizer servings

Vegetables :

½ small yellow onion, peeled
2 Japanese eggplants
8 shiitake mushroom caps
8 oz (250 g) asparagus, blanched
8 slices lotus root, peeled and blanched
1 small carrot, peeled and cut into 2-in (5-cm) lengths
½ avocado, cut into 8 wedges
8 shiso (perilla) leaves
Vegan Tempura Batter
½ cup (75 g) all-purpose flour
½ cup (75 g) potato starch or cornstarch (corn flour), plus more for dusting
1 cup (125 ml) cold carbonated water
Pinch of salt
Handful of ice cubes
Oil for frying
1 teaspoon grated ginger
1 teaspoon grated daikon radish
Tempura Dipping Sauce (page 26), if desired
Insert toothpicks or short skewers through the onion at ¼ inch (6 mm) intervals. Cut the onion into slices between the toothpicks or skewers. Set aside.
Cut each Japanese eggplant in half lengthwise. Make three long cuts in each half to produce a fan shape. Set aside.
Use a sharp knife to remove a crosshatch section from the top of each shiitake mushroom cap. Set aside.
Have all other vegetables ready. Heat at least 2 inches of oil in a skillet or wok to 350°F (175°C).
Make the tempura batter: In a small bowl, stir together the flour, potato starch, carbonated water, and salt. Add the ice cubes. The batter will be thin.
Dredge three or four vegetable pieces in potato starch and shake off the excess.
Dip the vegetable pieces into the cold batter. You should still be able to see the vegetables through the batter.
Gently slide the dipped vegetables into the hot oil. Be careful not to drop ice into the hot grease. Fry until crisp, about 2 minutes. The eggplants will need to be flipped over and fried for about 2 minutes more.
Use a slotted spoon to remove vegetables from oil. Allow to drain on a wire rack. Discard the beads of batter that float in between batches.
Repeat with remaining vegetable pieces, a few at a time, monitoring the heat of the oil.
Arrange cooked Vegetable Tempura on a platter. Serve with warm Tempura Dipping Sauce, if desired, with grated daikon radish and ginger on the side.