Boil the potatoes in salted water for 15-20 minutes or until tender. Drain well, return to the pan and set over a low heat for 2 minutes to drive off moisture.
Preheat the oven to 220ºC, gas mark 7. Arrange the potatoes on 2 baking trays then, using the base of a bowl, squash them so they still hold together but are smashed and flattened. Season, drizzle with the oil and roast for 35-40 minutes, swapping the trays halfway, until crisp and dark golden brown.
Meanwhile, in a bowl, mix together all the ingredients for the dressing. Transfer the potatoes to a serving bowl, then scatter over the shallot rings. Drizzle over the dressing, then top with the peanuts and coriander; serve straight away with roast chicken or fish.
