Peel and cut the potatoes into large chunks. Rinse them thoroughly to remove excess starch.
Assemble the potato ricer and place the potato chunks inside. Press down firmly to rice the potatoes into a large bowl.
Grate the onion and add it to the riced potatoes. Mix well to distribute the onion evenly.
Sprinkle in the flour, salt, and black pepper. Stir until the ingredients are well combined and the mixture starts to hold together.
Divide the potato mixture into 8-10 equal portions. Shape each portion into a patty about ½-inch thick.
In a large skillet, heat a generous amount of vegetable oil over medium-high heat.
Carefully place the hash brown patties in the hot oil. Cook for 3-4 minutes per side, or until they are golden brown and crispy.
Remove the hash browns from the oil and drain them on paper towels. Serve immediately with your favorite breakfast companions.