Steps
1. Heat olive oil in a skillet over medium-high heat.
2. Season the beef with salt and pepper, then place it in the skillet. Cook for about 3-4 minutes on each side for medium-rare, or until your desired doneness.
3. Remove the beef from the skillet and let it rest.
4. In the same skillet, add sliced onions and minced garlic. Sauté until the onions are translucent and fragrant, about 3-4 minutes.
5. Slice the rested beef and return it to the skillet with the onions and garlic, mixing well.
6. Sprinkle cheese over the beef mixture and cover the skillet. Allow the cheese to melt for 2-3 minutes.
7. Serve hot, garnished with fresh parsley if desired.