Place the potatoes in a pot, cover them with water and season the water abundantly with salt. Bring to a boil and cook the potatoes until a fork slides in and out of them easily. Drain potatoes and cool.
Coat a large saute pan generously with olive oil. Add the onions, season with salt and bring the pan to a medium high heat. Add the crushed red pepper flakes and saute for 7 to 8 minutes or until the onions are soft and wilted but do not have any color.
Using the heel of your hand, smash the boiled potatoes to flatten and to break apart. Add to the pan, toss with onions and then flatten them against the bottom of the pan so they begin to form a crust. Repeat this process a few times so a lot of crust forms. Season with salt and toss with the chopped parsley.