Step 1 of 9
Make the tentsuyu first. Combine dashi, soy, and mirin in a small saucepan. Bring to a simmer for 30 seconds; pull off. Divide between four small bowls. Let cool.
Step 2 of 9
Heat the oil in a deep heavy pot to 180°C / 350°F. Use a thermometer; tempura is unforgiving on temperature.
Step 3 of 9
Mix the batter at the last possible moment. Whisk the egg into the ice water in a bowl. Sift the flour over the top. Stir with chopsticks just until barely combined — the batter should be lumpy with dry pockets still visible. Over-mixing develops gluten and ruins the crisp.
Step 4 of 9
Pat the shrimp and vegetables completely dry. Dust lightly with extra flour.
Step 5 of 9
Dip vegetables in the batter one piece at a time. Lower gently into the oil. Don't crowd — 4–5 pieces at a time. Fry 2 minutes for thin vegetables (sweet potato slices, mushrooms), 3 minutes for thicker (squash, eggplant).
Step 6 of 9
Shiso leaves get batter only on the underside (the smooth side stays bare). Fry 60 seconds.
Step 7 of 9
Shrimp last. Dip in batter, fry 2 minutes until the batter is barely tinted gold and the shrimp pink-curled.
Step 8 of 9
Drain on a rack — never on paper towels, which trap steam and soften the crust.
Step 9 of 9
Serve immediately on a folded paper square (kaishi) over a wooden board. The dipping bowls of tentsuyu with grated daikon and ginger stirred in, alongside.
Ingredients 15
the protein
- 12 large prawns, peeled with tails on, deveined, sliced underside (so they don't curl)
the vegetables
- 1 small sweet potato, peeled and sliced 5 mm thick
- 200 g kabocha squash, seeded, sliced 5 mm thick
- 8 shiitake mushrooms, stems removed
- 1 small Japanese eggplant, halved lengthwise, scored
- 8 large shiso leaves
the batter
- 200 g tempura flour (or 150 g cake flour + 50 g cornstarch)
- 300 ml ice water (with ice cubes in the measuring jug)
- 1 large egg, lightly beaten
the fry
- 1.5 L neutral oil (or 50/50 with sesame oil for fragrance)
the tentsuyu
- 300 ml dashi
- 60 ml soy sauce
- 60 ml mirin
the serve
- 100 g grated daikon, drained
- 1 tbsp grated ginger