Season the steak with garlic powder, oregano, salt, and pepper. Heat the oil in a skillet over medium heat. Add the steak and sear for 5-7 minutes per side, until cooked to your desired doneness (medium-rare is about 135°F / 57°C).

Transfer the steak to a cutting board and let it rest for 5 minutes, then slice thinly against the grain.

Stuff the sliced steak into the pita(s) along with the cucumber and tzatziki. Serve.

Meal Prep Tip: For best results, store the components (cooked steak, tzatziki, sliced cucumbers, pitas) separately if prepping for multiple days. Reheat the steak briefly before assembling.