Peel and grate the russet potatoes using a box grater or food processor. Rinse the grated potatoes in cold water to remove excess starch. Drain and pat them dry with a clean kitchen towel.

1. If using, sauté the chopped onion in a large skillet with 1 tablespoon of olive oil or butter over medium heat for 3-5 minutes, until soft and translucent.
2. Add the remaining tablespoon of olive oil or butter to the skillet and heat over medium-high heat.
3. Once the oil is hot, add the grated potatoes. Spread them out evenly and press down gently with a spatula. Season with salt and pepper.
4. Cook for 5-7 minutes on one side until golden brown and crispy. Then flip the hash browns in sections, or flip the whole batch at once using a large spatula. Cook for another 5-7 minutes until both sides are crispy and browned.
5. Remove the hash browns from the skillet and place them on a paper towel-lined plate to absorb any excess oil. Garnish with fresh herbs, if desired, and serve immediately.