Tempura asparagus with sweet soy dipping sauce

1. First, make the dipping sauce by whisking together all the ingredients in a small bowl. Taste and adjust to your liking by adding more chilli heat, acidity or sweetness.

2. Half-fill a wok or medium-sized saucepan with the oil, or prepare a deep-fat fryer. Heat until it reaches 180°C on a thermometer, or test by dropping a small cube of bread into the oil – it should take 20 seconds to brown.

3. While the oil heats up, prepare the tempura batter. Sift together the flour and cornflour into a mixing bowl and add ½ tsp salt. Make a well in the centre, then gradually add the chilled sparkling water, whisking all the time to make a batter (don’t worry if it’s not perfectly smooth).

4. Snap any woody ends off the asparagus and discard. Dust with the remaining flour so each piece is roughly coated. Set aside. Line a baking tray with kitchen paper, to drain the cooked spears.

5. Dip each spear into the batter, then fry for 2 minutes until crisp. Remove with a slotted spoon or tongs, and place onto the prepared tray. Continue cooking in batches, until the batter is used up. Serve immediately with the dipping sauce.