Papas Rellenas — Tuna-Stuffed Potato Croquettes · Karlos Arguiñano

Lower 3 eggs into a pan of simmering salted water and cook them for 10 minutes. Then cool them under running cold water, peel, and chop them small.

💡 Cooling them under cold water is not only about handling — it stops the cooking and keeps the yolks yellow instead of that grey-green ring.

Drain the two tins of tuna and tip the fish into a bowl. Break it up thoroughly with a fork until there are no compressed lumps left.

Add the chopped hard-boiled egg and the glass of tomate frito to the tuna and mix until it looks like one even, spoonable filling. Set it aside in the fridge.

💡 Chilling the filling firms it up and makes the stuffing step much less fiddly. A loose, warm filling squeezes out of the sides as you close the potato around it.

Put the whole unpeeled potatoes into a large pot, cover generously with cold salted water, bring to the boil and cook about 30 minutes, until a skewer meets no resistance in the middle.

💡 Cooking them whole and in their skins keeps water out of the flesh. Cut potatoes boil faster but come out sodden, and sodden potato will not hold a filling.

Drain, let them cool just enough to handle, then peel — the skins should slip off with your thumb — and pass the flesh through a ricer into a big bowl.

💡 Rice them while still warm. Fully cold potato goes sticky under pressure and you lose the light texture that makes these good.

Season the riced potato with salt and mix it well with a spatula. Taste it — it should already taste good on its own.

Now let the potato cool completely — spread it out in a wide dish so it loses heat faster. This can take 30 minutes or so.

💡 Do not skip this. Warm potato dough refuses to hold a shape and the breadcrumb coating slides straight off it in the pan.

Take a handful of the cold potato, roll it into a ball, then flatten it on your palm into a disc about 1 cm thick.

Spoon a mound of the tuna filling into the centre, then bring the edges of the disc up and over it and pinch them shut. Roll it between your palms into a large croquette shape. Make 8 in total.

💡 Check the seam with your fingertips. Any crack, however small, is where hot oil gets in and filling gets out — patch it with a little extra potato.

Line the eight up on a tray and chill them for 20 minutes if you have time.

Roll each one in beaten egg, letting the excess drip off, then in breadcrumbs, pressing all over so no potato shows through.

💡 Look for bald patches and go back over them. This coating is the only thing holding a soft potato ball together in hot oil.

Heat plenty of olive oil in a deep pan until a breadcrumb bubbles briskly on contact — around 180°C. Fry the papas a few at a time, turning them, until they are an even deep gold all over.

💡 Everything inside is already cooked, so you are only after colour and a crust — about 2–3 minutes. Longer and the potato inside starts steaming and pushing at the seam.

Lift them onto kitchen paper and leave them for a minute — the inside is molten hot right now.

Make the mayonnaise: crack 1 egg into the tall beaker of a stick blender, add 1 tablespoon of vinegar, a good pour of olive oil and a pinch of salt.

💡 Everything must be at the same temperature — a fridge-cold egg with room-temperature oil is the classic reason mayonnaise splits. Take the egg out 20 minutes ahead.

Put the blender head flat on the bottom of the beaker, blend without moving it until the base turns thick and pale, then lift it slowly to pull the rest of the oil in.

💡 Blitzing straight away with the head moving is how you get soup. Bottom first, hold it there, and only then lift.

Serve two papas per plate — cut one of them in half so the filling shows — with a spoonful of the mayonnaise and a sprig of parsley.