Simmer the potatoes until just tender and drain. Meanwhile grill the bacon until crisp. Cut the tops off each potato and carefully scoop out the flesh and set aside. Cut thin strips off each of the potato bases so that the potatoes can stay upright & place in a lined oven-proof dish or baking tray. Then combine the potato flesh with the butter & grated cheddar, stir in the bacon and season to taste. Carefully spoon the filling back into the potato shells and replace the potato tops.
Brush liberally with the olive oil and bake in the oven until golden - about 10- 15 minutes at 200 C gas 6. Garnish with herb sprigs and serve warm from the oven.