Cook the potatoes in salted water until soft, drain and reserve 300 ml of the cooking water. Allow the potatoes and cooking water to cool separately. Pass the potatoes through a food mill. Add the flour, reserved potato water, mashed potatoes, salt, yeast and oil, knead into a soft, smooth dough using the dough hook on a food processor for approx. 10 mins. on the lowest setting. Cover and leave to rise at room temperature for approx. 1 hr. until doubled in size.
Divide the dough into 6 portions, shape into bread rolls (each approx. 15 cm long). Transfer to a baking tray lined with baking paper, leave to rise for approx. 30 mins. Brush the rolls with milk.
Approx. 35 mins. in the lower half of an oven preheated to 200°C. Remove from the oven, leave to cool on a cooling rack.
Prepare the fondue according to the instructions on the packet, stir in the herbs. Cut open the rolls at one end. Scoop out the insides, leaving a border of approx. 1 cm. Pour in the fondue.