Step 1: Prepare Marinade - In a medium bowl, whisk together soy sauce, Worcestershire sauce, minced garlic, black pepper, onion powder, and salt until well combined.

Step 2: Marinate Beef - Add beef strips into the marinade, ensuring each piece is coated. Cover and marinate for at least 15 minutes.

Step 3: Heat Pan - Place a large skillet over medium-high heat. Add olive oil and heat until shimmering.

Step 4: Cook Beef - Add marinated beef strips to the hot skillet in a single layer, cooking for 3-4 minutes on each side.

Step 5: Add Butter - Reduce heat to low and add unsalted butter to the skillet, stirring gently to coat the beef.

Step 6: Finish with Herbs - Sprinkle freshly chopped parsley over the beef and stir gently.

Step 7: Serve - Transfer Butter Beef to a serving platter and serve immediately.