Instructions

1. Prepare ingredients: slice sweet potato, kabocha, lotus root into 5-7mm thin slices. Cut eggplant into long sticks. Trim beans/asparagus. Pat all pieces very dry (moisture causes splatter).
2. For shrimp: peel leaving tail and last shell segment. Devein. Lightly score belly side and gently straighten. Pat very dry and dust lightly with flour before battering.
3. For fish/squid: pat very dry and dust lightly with flour.
4. Make dipping sauce (tentsuyu): combine 180ml dashi, 3 tbsp soy sauce, 2 tbsp mirin, and 2 tsp sugar (if using) in small pot. Bring just to boil, turn off heat, and let cool to warm/room temperature.
5. Make batter: Use cold bowl and keep all ingredients very cold. Prepare ice cubes.
6. Lightly beat 1 cold egg - do not whip until frothy.
7. Add 150ml cold water + 100ml ice-cold carbonated water to egg, then add ice cubes.
8. Add sifted 100g flour + 30g cornstarch all at once.
9. Using chopsticks, mix very briefly (about 10-15 gentle strokes). Some small lumps are fine. Do not overmix; this develops gluten and makes batter heavy.
10. Keep bowl over ice or in fridge between batches so batter stays cold.
11. Heat 4-6cm oil in deep, heavy pot to 170-180°C (338-356°F). Test: drop small batter piece in; it should sink slightly then quickly float and bubble briskly.
12. Lightly dust ingredients in flour just before dipping; tap off excess.
13. Dip in batter right before frying; do not let sit in batter.
14. Fry similar items together in small batches; do not overcrowd to keep temperature stable.
15. Gently turn once as needed. Cooking times: shrimp 1.5-2 minutes; thin vegetables 1-2 minutes; denser slices (sweet potato, kabocha, lotus) 2-3 minutes until just tender.
16. Remove when pale golden, not dark brown. Drain on rack or paper towels; do not stack.
17. Skim loose batter bits from oil between batches to avoid burning.
18. Serve immediately while hot and crisp with tentsuyu sauce and optional grated daikon on the side.