Welsh wagyu burger with fermented lettuce

To begin, make the fermented lettuce as this will need to be started way ahead of serving. Place the lettuce in a vacuum bag with a pinch of sea salt, seal, and leave at room temperature for around 3 weeks depending on the weather (warmer weather requires a shorter time, colder weather will need a longer time to ferment). After 3 weeks, the bag should have inflated. Check the lettuce with a digital pH tester or litmus paper – it needs to reach a pH of 3 to ensure it has fermented properly. Once fermented, remove the lettuce (retaining the liquid that has been released in the bag and cut into quarters. Cut each quarter into slices, place in an airtight container with the ferment liquid and seal. This will keep in the fridge for a number of weeks

For the burger, combine the raw shallot, garlic and minced wagyu beef in the bowl of a stand mixer and mix with a paddle attachment until combined (you can also do this by hand with a little elbow grease). Cook off a piece of the mixture to check for seasoning and adjust accordingly with sea salt. Once seasoned, set the mixture in a container so the mixture is about 4cm deep. Place in the fridge to chill and set

For the mayonnaise, add the egg yolks, vinegar and mustard to a blender and blitz to combine. With the motor running slowly, gradually add the oil in a slow, steady stream to creation an emulsion. Add salt to taste

Break the bread into pieces and add to the blender. Blitz on a high speed until you have a smooth purée. Check the seasoning and, if needed, season with a little rice wine vinegar and white pepper. Store in a piping bag until ready to serve

To prepare the pickles, combine the sugar and vinegar in a container, stirring to dissolve the sugar. Add the cucumber and shallots and set aside for 1 hour before serving

Remove the burger mixture from the container and cut into 5 x 5cm squares. Return to the fridge until ready to cook

Toast the sesame seeds in a hot, dry pan until golden. Immediately remove from the pan, allow to cool then place in a small blender or spice grinder. Briefly blend to break them up a little and set aside. Drain the cucumber pieces from the pickle and char in a hot, dry pan until starting to blacken in places

When ready to serve, cook the burgers in a pan over a medium-high heat until cooked through to medium and a deep golden colour on the outside. Place on the barbecue for 30 seconds to create a nice smoky flavour

Place a burger in the centre of each plate, top with a slice of fermented lettuce and pipe over some bread mayonnaise. Finish with the pickled cucumber, shallot and some toasted sesame seeds