Rub the sweet potatoes in olive oil and salt and place in a roasting pan.
Bake for roughly an hour or until potatoes are cooked through and skins are slightly charred.
While the potatoes are baking make the rosemary salt. Add a table spoon of the sea salt to a Mortar & Pestle and pound to break up, then add the rosemary a little at a time, tasting along the way to make sure the rosemary doesn’t over power too much. Set aside.
Once the potatoes are ready, remove from oven and allow to cool slightly. With a knifes peel the skins off in chunks so that some of the flesh stays on the skins. Put the skins on a tray and put them in the fridge for a couple of hours.
When you are ready to cook them either: Preheat a deep fryer to 180C or place canola oil in a fry pan so that its deep enough to cover the skins and heat to 180C or drop a piece of bread in to test.
Fry the skins for a few minutes until crispy and drain briefly on paper towel – toss in rosemary salt and serve on rack or similar so they skins don’t sweat.
You will also need: Mortar & Pestle Depp fryer or deep frypan