Place the potatoes in a saucepan, add in the salt and the vinegar. Pour enough water to cover the potatoes by at an inch in depth.
Boil the potatoes on high heat until the potatoes are tender (approximately 25 minutes). You can check if the potatoes are ready by inserting a skewer into the middle, it should pierce through easily. Preheat oven to 220°C (430°F) or 200°C (390°F) for fan-forced ovens.
Remove the potatoes out of the water and place them on a cooling rack for 10 minutes. The steam will help the potatoes dry up, the dryer the potatoes are, the crispier it'll be when baking.
Use a potato masher or the bottom of a mug to flatten the potatoes, take care not to squish them too flat or they may fall apart. Leave the potatoes to steam dry for another 5 minutes.
Pour the oil into a large baking tray, make sure the oil covers the entire surface of the tray. Place the potatoes in a singer layer on the tray. Carefully flip over the potatoes using a spatula, this will grease both sides of the potatoes with oil. Lightly sprinkle the potatoes with salt and bake for 40 to 45 minutes or until they are nice and golden. There is no need to flip the potatoes during baking.
Use a spatula to remove the potatoes from the tray and place them in a bowl, add in the vinegar, parsley (if using) and salt (if needed) to taste. Toss the potatoes gently and serve immediately.
Notes
(NOTE 1) Potatoes - Any variety of baby potatoes will work but try to select potatoes that are roughly the same size so they'll cook more evenly. I've previously tried white, red and royal blue baby potatoes using this recipe, my favourite was the red ones because they were creamy on the inside and crispy on the outside.(NOTE 2) Vinegar - You'll need a cup of vinegar to boil with the potatoes, so there's no need to waste your expensive organic apple cider vinegar! Cheap white vinegar works fantastic. (NOTE 3) Olive oil - I prefer using the mild or light tasting olive oil when cooking as it's more subtle tasting.A Third-Party Application calculated the calories and nutritional information, so this is an approximate guide only.Cooking measurements are in Australian standard spoon and cup measurements.