01 - Combine beef strips, soy sauce, olive oil, black pepper, and garlic powder in a bowl. Toss thoroughly and let marinate for 10 minutes.
02 - Warm vegetable oil in a large skillet or wok over high heat.
03 - Add marinated beef in a single layer. Sear without stirring for 2 to 3 minutes to develop color, then stir-fry for an additional 2 to 3 minutes until just cooked through.
04 - Remove from heat and transfer beef to a serving plate. Garnish with parsley and lemon wedges if desired.