Preheat the oven to 200g
Wash and scrub the potatoes and then dry them off with a clean towel.
Make slices across the potatoes about 3-5mm apart, being careful not to cut all the way through the potato.
Mix together the oil and the vinegar and a good twist of salt and pepper.
Lay the potatoes in a roasting dish, so the cut side is facing up and drizzle over in the oil and vinegar mix.
Bake in the oven for about an hour until the centre is cooked through, they may need longer depending on their size.
In the meantime, to make the sweet tomato sauce, simply fry the onion in the olive oil for 4-5 minutes until just turning brown and then add the garlic for a further minute.
Add all the remaining ingredients, bring it to the boil and them simmer for 10 minutes, stirring occasionally.
Remove the sauce from the heat and leave to cool slightly before whizzing into a paste.
Mix together the grated cheese, the garlic and a good twist of black pepper and shape into 6 flatish surfboard shapes, so they will lie over the top of the potato.
When the potatoes are cooked, place the cheese on top of each potato and place under the grill until the cheese has melted.
Plate up with the dipping sauce and enjoy.