Heat olive oil in a large skillet over high heat. Lightly season the steak cubes with salt and pepper.
Place the steak pieces in the skillet in a single layer. Work in batches if necessary to avoid overcrowding. Sear for 3-4 minutes, stirring occasionally, until the meat is golden brown.
Add the butter and minced garlic to the pan, stirring to coat the steak in the fragrant sauce. Cook for an additional 1-2 minutes.
Garnish with parsley and serve immediately.