Step 1 In a large bowl, thoroughly combine the mashed potato with the watercress, capers, gherkins, lemon zest and squeeze of lemon, horseradish and mustard. Flake in the mackerel, stir it through and season to taste with salt and pepper. Chill while you prepare the eggs.

Step 2 Boil four eggs for 3.5 minutes. When the eggs are ready, immediately plunge them into a bowl of iced water. When thoroughly chilled, peel them and roll them in 3 tbsp flour until coated.

Step 3 Take a piece of cling film large enough to fold around an egg. Spoon a quarter of the mackerel mixture over it into an evenly distributed circle. Put an egg in the centre and pull the cling film around the egg tightly so there are no gaps of mackerel mixture around the egg. Remove the cling film and repeat with all eggs.

Step 4 Place the plain flour in a bowl. Beat the two remaining eggs with the smallest dash of water in another bowl. Finally, place the breadcrumbs in a third bowl.

Step 5 Dip each egg into the flour, then into the eggs, finally into the breadcrumbs until thoroughly coated. Set aside on a lined baking tray.

Step 6 Heat the vegetable oil to 170c. Submerge the eggs, two at a time, for approx 7 minutes until golden all over. Place on a tray lined with kitchen roll to absorb any excess oil.