In a large bowl, combine the steak cubes, olive oil, salt, and black pepper. Toss to coat the steak evenly.
Heat a large skillet over medium-high heat. Once hot, add the steak cubes in a single layer, making sure not to overcrowd the pan. Cook for 2-3 minutes without stirring until browned.
Flip the steak bites and cook for another 2-3 minutes until browned on the other side and cooked to your desired doneness (medium-rare is about 130°F).
Reduce the heat to medium and add the minced garlic and butter to the skillet. Stir to combine and cook for an additional 1-2 minutes until the garlic is fragrant and the butter is melted.
Remove from heat and sprinkle with fresh parsley before serving.