1. Add all the flour to a bowl. Mix with the handle of a spoon and stir in the ice-cold water until the mixture is slightly thicker than buttermilk consistency. Don't mix thoroughly, as tempura is renowned for lumps of flour.
2. Dip sliced vegetables (zucchini, onions, eggplants, carrots, bell peppers, sweet potatoes, string beans, broccoli, wild mushrooms, fresh herbs, and bok choy etc) into the batter mixture, shake off any excess.
3. Deep fry vegetables in a wok or deep fat fryer until the batter is light golden in color and crisp.
4. Turn the vegetables at intervals to ensure that all sides are cooked equally. When cooked remove with a slotted spoon, shaking off any excess oil.
5. Place them on kitchen paper towels and eat as soon as possible. Tempura should be crispy and is one of those things that should be made and cooked quickly and eaten straight away.
Tempura Dipping Sauce:
1. Pour the rice wine vinegar into a small bowl.
2. Add the sugar and stir until dissolved. Taste for sweetness.
3. Add cilantro, chilli, and garlic and mix well. Season with salt and pepper and allow to sit for 10 minutes to 1 hour, for flavours to combine.