Add the potatoes to a pot, and cover with water by a 1/2". Generously salt the water. Bring the mixture to a boil and let the potatoes cook for 2 minutes. our the potatoes into a strainer to drain, and let rest for 5 full minutes.
Add 1 tbsp of oil to a large cast iron skillet, and heat it over medium heat. When the oil's nice and hot, stir in the onions. Cook until the onions are soft and translucent, about 5 minutes. Transfer the cooked onions to a separate plate, and return the skillet to the stove.
Add the rest of the oil and the butter to the skillet, again heating over medium heat. When the oil's nice and hot, add the potatoes- tossing evenly to coat with the oil and butter.
Use a spatula to spread the potatoes out into a single layer. Cook for 10 minutes, only stirring once half way through, so everything gets nice and crispy.
Sprinkle to garlic, paprika, salt & pepper evenly out over the potatoes. Add the onions and stir until everything is evenly combined.
Serve immediately, alongside your other breakfast favorites.