Step 1

Heat a skillet over medium heat and add the canola oil. Add the onions, season with a pinch of salt and cook, stirring frequently, until the onions are golden brown, 15 to 20 minutes.

Step 2

Meanwhile, season the potatoes with salt and pepper and let sit for 5 minutes. Drain out the excess moisture.

Step 3

Set individual cast-iron pans over medium heat until very hot. Add some olive oil to each pan and a handful of the potatoes. Cook until golden brown and crispy, about 5 minutes. Flip and add more oil if necessary. Cook until golden brown on the second side and cooked through. Repeat with the remaining potatoes.

Step 4

Top each hash brown with some caramelized onions and a dollop of sour cream and chopped scallions.