Step 1

Peel and dice 16oz/450g white potatoes and place in a pot of enough cold water to comfortably cover them. Add a hefty pinch of salt and bring to a boil until they are just about tender enough to slice. It's crucial you don't over boil the potatoes or they'll soak up too much water and the patties will be too sloppy to mould.

Step 2

Drain in a colander and allow to steam completely dry. This is crucial to allow as much moisture to leave the potatoes as possible. If you have time cool them completely in the fridge, do that as well, but the main thing is allowing all the steam to escape. Mash until lump free.

Step 3

Combine your cold mash with butter, mustard and mayo. Add in tuna, spring onions, parsley, lemon zest, garlic powder and seasoning to taste. If you're using leftover mashed potato which was made with butter you won't need to add more. Also just take into consideration how much it was already seasoned.

Step 4

Mould into equal burger-shapes, you should get 6-8 depending on size. I find scooping with a 1/3 measuring cup gives 6 equal patties. I highly recommend popping them in the freezer at this point for 10-15mins to firm up before dredging. Or at least while you set up your bowls.

Step 5

Set up your stations: 1 bowl with flour and a pinch of salt and pepper, then 1 with your beaten egg and lastly breadcrumbs with a pinch of salt and pepper.

Step 6

One by one, delicately (but still thoroughly) coat the patties in flour, then egg, then breadcrumbs. Again, if they feel at all flimsy at this point pop them in the freezer to firm up.

Step 7

Pour enough veg oil in a pan to comfortably cover the entire surface. Bring to a medium-high heat and when it sizzles when a crumb is dropped in, carefully place in 3 patties at a time. Allow to fry for 3-4mins (or until golden underneath) then flip and fry until golden on the other side. It's important that the oil is hot enough to 'sizzle' when the patties hit the pan. If it's too low, the patties will merely soak up the oil, become soggy and fall apart.

Step 8

Place on a greased tray and liberally spray with oil. Bake at 390F/200C for 20-25mins, flipping once, or until golden and crispy all around (timings will vary depending on size of patties).

Step 9

See recipe notes for make ahead and freezing options.