In a large mixing bowl, combine the grated potatoes and onion. Add the flour, beaten egg, salt, and pepper. Mix until well combined.

Heat the vegetable oil in a frying pan over medium-high heat. Once the oil is hot, spoon the potato mixture into the pan, forming small patties.

Cook the potato rosti for about 3-4 minutes on each side or until they are golden brown and crispy.

Remove the rosti from the pan and place them onto a paper towel to absorb any excess oil.

Serve the potato rosti hot with your favorite toppings like sour cream, cheese, or smoked salmon. Enjoy!