Remove the woody core from the cabbage. Separate the leaves, and cut out the tough stem. Stack the leaves, and shred as finely as possible.
Top and tail the carrot, and peel. Slice the carrot lengthwise as thinly as possible. Stack a few slices and cut into a julienne.
Slice the apple, and cut into batons.
Combine the cabbage, carrot and apple together, season with the salt.
Trim the spring onions, and cut into thin slivers. Set aside.
Juice the lemon.
Whisk together the egg yolk, mustard and lemon juice. Season with salt and pepper.
While whisking continuously, drizzle in the oil until you obtain a thick mayonnaise.
When ready to assemble the coleslaw.
Mix in all spring onions and a few spoonfuls of the mayonnaise.
Taste and adjust the seasoning if necessary. If the coleslaw looks a little dry, add more mayonnaise.
«The flavour of the coleslaw mellows out with time, so make it a day or two ahead for a party or a picnic.»