Grate the potatoes and rinse them under cold water to wash off extra starch. Squeeze the grated potatoes dry using a clean kitchen towel or paper towels. Heat butter and oil in a large skillet over medium heat. Spread the potatoes evenly in the skillet and press them down lightly. Season with salt and pepper.
Cook for 5–7 minutes, until the bottom is golden and crispy. Flip carefully (in sections if needed) and cook the other side until crispy.
Sprinkle cheese on top while the hashbrowns are hot so it melts.
Add bacon, eggs, green onions, and a spoonful of sour cream.
Top with extras like avocado, hot sauce, jalapeños, or chives.
Serve right away while the bottom is still crisp and the top is rich and melty.