2) Put the potatoes into a large pan, cover with water and add salt. Set the heat on high and boil until the potatoes are fork tender.
3) In a large saute pan over a medium heat cook the bacon and saute the onions until caramelized. Leaving the bacon fat in the pan, remove the bacon and onions onto a paper towel to absorb the grease, then keep warm on a serving platter.
4) When the potatoes are fork tender, drain, and with a clean kitchen towel palm smash the hot potatoes to approximately 1cm thick.
5) Reheat the fat in the saute pan and add 2 tbsp of olive oil. Heat to medium heat and then place the potatoes in the oil. Season with salt and pepper and brown on both sides.
6) Transfer the potatoes to the serving platter with the onion and bacon. Repeat until all the potatoes are cooked crispy.
7) Top the potatoes with the Parmesan, followed by the sour cream mixture, and serve.