To prepare the prawn cocktail, start with the mayonnaise: place the egg yolk in a bowl, then add the lemon juice (1), salt, and pepper (2). Turn on the electric whisk and slowly pour in the ...

Done right, a prawn cocktail is a beautiful Christmas starter - and John Torode's the man to show you how. Bring a large pan of water to the boil and add a squeeze of lemon and glug of vinegar.