In a large bowl add the parsley, olive oil, garlic, oregano, lemon juice, salt and pepper. Whisk well to combine.
Cut steak into 1 inch cubes. Place cubed steak in the marinade stirring to coat all the steak pieces. Cover bowl with lid and place bowl in refrigerator. Let marinate at least 2 hours or over night.
Heat a large non-stick skillet, or cast iron skillet (that's my favorite to use), over medium-high heat. When pan is hot add the steak pieces to skillet, discarding the remaining marinade.
I like to cook mine for 4 to 5 minutes for a medium doneness. Cook longer if you like your steak well done.
Serve immediately and enjoy!