Place chopped potatoes and the pinch of salt in cold water in a large saucepan, ensuring the potatoes are completely covered with water.
Place saucepan on stovetop and bring to the boil. Then reduce heat to medium-low and simmer for 10 to 15 minutes, or longer, until potatoes can easily be pierced with a knife. The potatoes should slide off the knife easily.
Once cooked, drain potatoes in a colander, reserving ½ a cup of the cooking water.
Place the still-hot potatoes and the ½ cup of cooking water into a large mixing bowl, and combine with the vinegar and salt. Let it stand to cool, gently stirring occasionally with a wooden spoon or silicone spatula that won’t cut into the potatoes. It will appear very watery for a while, but the potatoes will absorb the water with time and reward you with moist and tangy potatoes. Be patient. It can take five to fifteen minutes for the potatoes to absorb the water completely. Alternatively, you can skip this step and double the olive oil in the dressing.
Meanwhile, whisk together the remaining ingredients, especially necessary if you add any of the below dressing additions.
Then stir through the potatoes once the potatoes have absorbed the moisture. Note that the herbs are best added immediately before serving, but it is not essential.
Serve warm, at room temperature or chilled from the fridge in a salad bowl or on a platter.