Wash the potatoes. If using baby potatoes, halve or quarter them. If using large potatoes, peel and chop them into 4-6 even pieces.
Place the potatoes in a large saucepan with a sprinkle of salt, then pour water on top so the water just covers them.
Cover the pan, bring the water to the boil then turn down the heat a little. Cook the potatoes for about 15 minutes, until cooked but not too soft.
Empty the potatoes into a strainer, run a bit of cold water over them then leave them to cool for about 20 minutes.
Wash the spring onions and chives.
Cut off the root ends of the spring onions, then chop up them up as finely as possible. Cut up the chives with scissors.
Once the potatoes are cool, chop these into smaller pieces.
In a large bowl, combine the potatoes, chives, spring onions and some salt and pepper, then mix in the mayonnaise.