Peel and halve the potatoes, then put them in a pot and cover with cold water. Add the salt, then bring the water to the boil over high heat. Turn the heat down and simmer for 20-25 minutes until the potatoes are tender.

Meanwhile, make the dressing by combining the onion and the cold vegetable oil in a small frying pan. Cook gently over medium heat for 5-10 minutes until the onion has softened, but not browned. Whisk together the vegetable stock, vinegar and mustard, then add to the pan. Bring the mixture to a simmer then remove from the heat and keep warm.

When the potatoes have cooked, drain and allow to dry with the lid on the pan for 2-3 minutes. It’s important now to prepare your working area so that you can get the potatoes cut and into the dressing while everything remains as hot as possible.

Place a large bowl next to a chopping board. Using a fork, tongs or wearing a washing-up glove as I do, take the potatoes one by one out of the pot, cut roughly, then scrape into the bowl, pouring over a little of the hot dressing every few potatoes. Repeat until all the potatoes and dressing have been used up.

Season well with black pepper then set aside, uncovered, for 30 minutes to 1 hour.

Before serving, season to taste and stir through any of the optional add-ins, if using.