Ingredients
4 large sweet potatoes 
Olive Oil 
Salt

Method
Wash the sweet potatoes with a sharp knife poke the sweet potatoes for the steam to escape.  Pour some olive oil into your hands and smother the potatoes in oil and then either cook on a little mound of rock salt on a baking tray or season them well all over with salt and place on a wire rack.  Put into a hot oven (190c) for 1-1 ½ hours or until soft.  

When you cut open the potato and smother with butter, don’t forget to season the inside.