2 bunches -
spring onions (a.k.a. scallions or salad onions)
directions
If necessary, scrub the potatoes, then boil them still in their skins in salted water until soft (about 30 minutes). Meanwhile, finely chop the spring onions. Drain and remove the potatoes from the pan. Leave until just cool enough to peel. Scoop out the inner potato with a spoon into a large bowl and discard the skins. Mash the potato thoroughly, using just a little of the milk if necessary to help the process (it needn't be totally smooth at this stage)
Heat the remaining milk and add to the potato, together with the chopped spring onions. Season with salt and white pepper to taste and stir well. Pile into a serving dish, make a well in the centre and add the butter. Serve immediately while the butter is melting.