Oyster tempura, green apple, wasabi & lime mayonnaise, shiso

‘Fill a serving platter with rock salt and sit the oyster shells on the salt’

Serves 4 as an appetiser

INGREDIENTS

• Tempura batter (see below)

• 100g tempura flour, to coat

• 1 tbsp wasabi paste

• 2 tbsp lime juice

• 150g mayonnaise

• vegetable oil, to deep-fry

• 12 live rock oysters

• 1 Granny Smith apple

• rock salt, to serve

• 1 punnet purple shiso cress, to serve (optional)

FOR THE MAYONNAISE

• 6 egg yolks

• 20g English mustard

• 40g Dijon mustard

• 35ml white wine vinegar

• 500ml vegetable oil

• 250ml olive oil

• Juice of ½ lemon, or to taste

FOR THE TEMPURA BATTER

• 300ml sparkling water, chilled

• 1 ice cube

• 150g tempura flour, plus more to dust

Start by making the batter, then leave it to rest for 30 minutes. When making tempura batter, it’s important that the sparkling water is chilled. To keep it cold, slide an ice cube inside the whisk. Place the flour in a bowl. Slowly whisk in the sparkling water a little at a time. The consistency should be light enough to just coat the oysters. Chill until ready to use.

To make the mayonnaise, whisk the egg yolks, mustards and vinegar in a large bowl, until well combined. Slowly drizzle in the oils, whisking continuously until the mixture thickens and emulsifies. Don’t rush this stage, or the oils won’t incorporate with the egg yolks and the mayonnaise will split. Add the lemon juice and season to taste. If the mayonnaise is too thick, add a touch of warm water. It keeps for two weeks in the fridge.

In a mixing bowl, whisk the wasabi and lime juice into the mayonnaise. Don’t adjust the seasoning yet, as you will add some of the salty oyster juice.

Once the batter has rested, set a deep-fat fryer to 170°C. If you don’t have a fryer, place the oil in a large, deep saucepan, leaving enough room at the top to allow for rapid boiling when the oysters are added. Place over a high heat, but be careful it doesn’t get too hot. If you have a cooking thermometer, use it to regulate the temperature. If not, test the heat by dropping in a cube of bread; it should bubble on entry and start to brown after 15 seconds. Have to hand some kitchen paper and a slotted spoon to remove the oysters from the hot oil (don’t try to use spring-loaded tongs – this can be very dangerous, for obvious reasons). Shuck the oysters (find a guide online, if you need it), then tip off the juices and reserve. Place the oysters into a colander and wash the bowl-shaped shells (discard the flatter half of the shells). Fill a serving platter with rock salt and sit the shells on the salt.

Strain the reserved oyster juice to remove any fragments of shell. Add enough of it to the mayonnaise to give a loose salad cream consistency. If you have a mandolin, use it to cut the apple into thin batons. If not, do so with a knife. Dress immediately with mayonnaise to prevent discolouration. Place a little apple into each shell, being generous with the dressing. Place the tempura flour into a bowl, and, one by one, coat the oysters with the flour, shaking off excess. Drop the floured oysters into the batter. When you’re ready to cook the oysters, lift them out one at a time, placing them carefully into the fryer with a spoon. Hold the oyster in the spoon submerged in the oil for a few seconds to allow the batter to set, before letting it go (this will stop it from sticking to the bottom).

Cook 6 at a time, or they will stick together. Deep-fry for about 2 minutes, until golden and crisp. Drain on kitchen paper to soak up any oil, before placing them on the dressed apple in the shells. You shouldn’t need to season. If you like, pick a few purple shiso tips and place them on top of each oyster to serve.