Vegetable Tempura Recipe

Prepare batter

Place a medium mixing bowl over another bowl filled with ice to keep it cold. Crack the egg into the chilled bowl and lightly beat once or twice to combine. Add the ice-cold water and stir gently. Sift together the all-purpose flour, rice flour (or cornstarch) and baking soda into a separate bowl. Sprinkle the fine sea salt over the dry mix. Add the dry flour mixture into the egg-water mixture in one go and stir very briefly with chopsticks or a fork — mix just until combined. Lumps are okay; do not overmix. Keep the batter cold by occasionally placing the bowl back over the ice.

Heat oil

Choose a heavy-bottomed pot or deep frying pan with at least 3 inches (7 cm) depth. Pour in the neutral oil and heat to 175–180°C (350–360°F). If you don't have a thermometer, test by dropping a pinch of batter into the oil: it should sizzle and rise to the surface quickly, turning pale golden in about 30–45 seconds.

Dry vegetables

Pat all vegetable pieces dry with a kitchen towel so batter adheres properly. If vegetables are wet, the batter will not crisp evenly and oil will spit more.

Fry in batches

Working in small batches (3–5 pieces depending on pot size), lightly dust larger pieces (like sweet potato and squash) with a teaspoon of flour to help the batter stick. Dip each vegetable into the batter to coat lightly — do not let excess batter drip off or keep it very thin for a delicate crisp. Gently slide pieces into the hot oil. Maintain oil temperature around 170–180°C (340–360°F). Fry until pale golden and crisp: thin vegetables 1–2 minutes, thicker slices 2.5–4 minutes. Turn pieces if necessary for even coloring.

Drain and keep crisp

Use a slotted spoon or spider to remove tempura to a wire rack set over a tray or to paper towels for a very brief drain. Avoid stacking pieces. Keep finished tempura warm in a low oven (about 90–100°C / 200–210°F) on a wire rack while you fry remaining batches. Re-check oil temperature between batches and adjust heat as needed.

Prepare vegetables as follows so they cook evenly: slice sweet potato and squash to about 1/8" (3 mm) thickness; cut eggplant and zucchini into 1/4" (6 mm) rounds; trim green beans; halve peppers and remove seeds; wipe mushrooms clean and leave small caps whole. Keep size consistent so frying times are predictable.

Lightly dust larger or moist vegetables (sweet potato, kabocha/squash, eggplant) with a little flour before dipping in batter to improve adhesion. For delicate items like shishitos, dip directly without additional flour.

Make tentsuyu while oil preheats: in a small saucepan combine dashi, light soy sauce, mirin and sugar. Bring to a gentle simmer over medium heat, stirring until sugar dissolves. Remove from heat and let cool slightly. If using instant dashi powder, follow package dilution to yield 1 cup first, then proceed. Place grated daikon and grated ginger in small bowls for guests to add to sauce to taste.

Keep the tentsuyu at room temperature or slightly warm. Serve in small individual bowls alongside the tempura.

Transfer tempura to a serving platter. Sprinkle a little finishing salt over the hottest pieces or provide salt at the table for guests. Serve with lemon wedges and the tentsuyu dipping sauce with optional grated daikon and ginger. Tempura is best eaten immediately while crisp.