I always use either goose fat or duck fat as it imparts flavour and has a higher smoking point. There is no specific recipe for roast potatoes, it is purely a technique.
Firstly I peeled 2kg of desiree potatoes and cut the potatoes into four if you prefer smaller roasties or into three if you prefer a larger roast potato.
I parboil the potatoes in water with a couple of tablespoons of salt in it, this is to give the potato flavour right the way through. Once the potatoes have boiled for 10 minutes, drain them immediately, leave the potatoes to sit for a further ten minutes so that the water has had a chance to evaporate. Place the potatoes back into the emptied pan and whilst placing the lid onto the pan shake the potatoes vigorously to rough up the outer layer of the potato. Place the duck fat into a pan and melt it, using a slotted spoon dip each potato into the melted fat and place onto a roasting tray, I call this the dip and dunk technique. Be careful not to overcrowd the tray so that you can allow the potatoes to crisp up evenly. Cook the potatoes in the oven for 35-45 minutes at 190 degrees c. This will feed 4-6 people.
They will be perfect.