Wash the potatoes. No need to peel them right now. Pressure cook on high for 5 minutes with an immediate release, or boil for 15-20 minutes until fork-tender.

Place the par-cooked potatoes in a large bowl and refrigerate for at least 2 hours until completely cool.

Prepare a 9x13 pan by lining it with parchment and spritzing with 0.5 Tablespoon of oil.

Peel the cool potatoes and grate them using a box grater. Do not use a food processor.

Add salt and cornstarch to the shredded potatoes and toss to coat.

Spread the potatoes into an even layer in the prepared pan and press down to compact.

Freeze the tray for 2-3 hours until firm, then cut into desired shapes.

Spritz with the remaining 0.5 Tablespoon of oil and freeze for at least 4 hours, or overnight for best results.

Air Fryer Method: Preheat at the highest setting for 10 minutes. Place frozen hash browns in a single layer and air fry at 375°F/190°C for 10 minutes. Flip and cook another 5-10 minutes until golden brown.

Oven Method: Preheat oven and cooking tray at 450°F/230°C (425°F/220°C for convection) for 10 minutes. Bake frozen hash browns for 7 minutes, flip, and bake another 7-10 minutes until golden.