Step 1
To prepare the perfect tuna mayonnaise jacket, start by preheating your oven to 200C/400F/Gas Mark 6. (We know lots of people cook their spuds in the microwave in a lot less time, but the oven method will give you a better cooked, better tasting potato, trust us.)
Step 2
Rub the two potatoes with a little olive oil, prick them with a fork just two or three times, and then place them directly onto the top shelf of your preheated oven. Bake for 1 hour and 15 minutes. Meanwhile, tip the tuna into a large bowl. Add the mayonnaise and stir well. Season the tuna mayo to taste and put to one side.
Step 3
When the potatoes have done their time and feel very crisp on the outside, yet soft on the inside, remove from the oven. Cut in half and scoop out all the boiling hot flesh and add it to the tuna mayo mixture. Also add the butter, then stir and season again.
Step 4
Now refill the jacket potato with the tuna mixture, sprinkle the four halves with a little grated cheese and put back in the oven – this time on a baking tray – for another 10 to 15 minutes. Serve immediately with a simple green salad.
