Scrub the potato and dice into small 1/2-inch cubes to ensure even cooking.
Heat the olive oil in a large cast-iron skillet or grill pan over medium-high heat.
Add the potato cubes to the pan and cook for 8-10 minutes, stirring occasionally, until they are golden and tender.
While the potatoes cook, slice the sirloin steak into thin strips and chop the bell peppers and onions.
Push the potatoes to one side of the skillet and add the steak strips, peppers, and onions to the other side.
Season the entire skillet with smoked paprika, garlic powder, sea salt, and black pepper.
Sear the steak for 3-4 minutes until browned and the vegetables have developed a slight char.
Toss all ingredients together in the pan and serve immediately garnished with fresh parsley.