In a large pan heat oil and cook beef and onion over a medium heat until the meat is no longer pink, add garlic and cook for an extra 1 minute.
Add chopped tomatoes and tomato paste, season with salt and pepper and leave to cook on medium heat for 15-20 minutes.
In the mean time start scooping out the inner of the potatoes till it becomes like a shell about 1 cm thick.
Carefully scoop the meat mixture into the potato shells and place them in a deep baking dish.
Place any left over meat mixture along with the inside of the potatoes around the potatoes then add the stock until you cover the stuffed potatoes.
You may need more or less stock depending on how big your potatoes or the size of your oven dish.
Preheat the oven to 170c then bake for 45 minutes then increase heat to 200c and bake for anther 30 minutes until the potatoes are tender and the stock is reduced.
