This recipe is from an Anonymous Griller.

1 small/medium sweet potato per person
Sunflower oil
Butter or margarine
Salt & freshly ground black pepper
Grated vegetarian Cheddar cheese to serve.

Scrub the sweet potatoes and brush lightly with a little of the oil. Wrap the potatoes individually in sheets of kitchen foil. Cook the potatoes for 40-60 minutes (depending on size and heat of the barbecue grill) until tender, turning from time to time. When cooked through, partially unwrap, split open and serve with butter or margarine, salt and freshly ground black pepper and grated cheese.