Dice the Russet potato into small 1/2-inch cubes to ensure even cooking and maximum surface area for crisping.
Heat the avocado oil in a large cast-iron skillet over medium-high heat until shimmering.
Add the diced potatoes to the skillet in a single layer; cook for 8-10 minutes, stirring occasionally, until tender and golden-brown.
Add the diced yellow onion and red bell pepper to the skillet, sautéing for 3-4 minutes until the vegetables are softened and fragrant.
Push the potato and vegetable mixture to the edges of the pan and place the ground beef in the center.
Break the beef apart with a spatula and season the entire pan with garlic powder, smoked paprika, sea salt, and black pepper.
Cook the beef until fully browned, then toss all ingredients together and let them sit undisturbed for 2 minutes to develop a final crispy crust.
Garnish with freshly chopped parsley and serve immediately.