Baking tiny new potatoes in a salt crust may seem a little excessive. However, not only does it make for an unusual and dramatic presentation but the sealed-in flavours become really intensified – moist and garlicky without being excessively salty.
Preheat the oven to 230°C/450°F/gas mark 8. In a bowl mix the salt, egg whites, rosemary sprigs and garlic together. Take a baking dish large enough to hold the potatoes in a single layer and spread a thin layer of the salt mixture over the base. Top with the potatoes and cover completely with the remaining salt mixture.
Bake for 30-35 minutes, until the crust is golden brown and risen. Leave to cool slightly and then crack the crust open with a kitchen hammer or a heavy knife to release the steamy hot potatoes. Brush off the salt and serve.