Peel (if you want) and cut potatoes into ½-inch cubes or thick wedges. Bring 2 quarts of water to a boil with ½ tsp baking soda and 1 tbsp salt. Add potatoes and simmer for 5 minutes, until fork-tender but not falling apart. Drain in a colander and shake it gently to roughen the surface.
Heat a large skillet for 3-5 minutes over medium heat. It should be very hot. Add the oil and heat it until shimmering hot and almost smoking, about 30 seconds. Add potatoes in a single layer and cook undisturbed for 5 minutes until the bottoms are golden brown.
Flip the potatoes and season with salt, pepper, and garlic powder if using. Fry for another 5 minutes, flipping occasionally, until crispy on all sides.
Garnish with fresh parsley and serve hot.
