Begin by peeling the two large russet potatoes using a vegetable peeler. Once peeled, grate the potatoes using a box grater or a food processor.

Soak the grated potatoes in a bowl of cold water for about 30 minutes to remove excess starch. After soaking, drain and thoroughly pat the potatoes dry.

In a mixing bowl, combine the well-dried grated potatoes with the all-purpose flour, salt, and pepper. Toss until evenly coated.

Heat a large skillet over high heat and add the vegetable oil and unsalted butter. Once the butter melts, add the potato mixture in a single layer, pressing down gently.

After 5-7 minutes, check for a golden-brown color on one side and carefully flip the hash brown. Cook the other side for an additional 5-7 minutes.

Transfer the crispy hash browns to a plate lined with paper towels to absorb excess oil. Serve hot.