Cut the potatoes (skin on, washed & patted dry) into thin rounds that are 1/8 of an inch (.3175 cm) thick
Add the sliced potatoes into a large bowl and fill with cold water, just enough to cover the potatoes
After at least 30 minutes, drain the potatoes and rinse them under cold water, then place them over a dishcloth (in a single flat layer) and pat completely dry
Line a baking tray with parchment paper, add the slices of potato, all in a single flat layer, then brush 1 tbsp (15 ml) olive oil over the slices of potato, making sure to brush them on both sides
Then season (just on one side) with sea salt, black pepper, garlic powder and dried rosemary
Add into a preheated oven (middle rack), bake + broil (bottom + top heat) option, 210 C - 410 F
After about 40 minutes, remove the potatoes from the oven, let them rest at room temperature for 5 minutes, then transfer into a serving dish, enjoy!