Preheat a grill or grill pan on medium heat.
Season the steak on both sides well with steak seasoning, salt, and pepper.
Cook the steak on both sides to your desired temperature using a thermometer. (see below) Once done allow the steak to rest on a cutting board for 3 - 5 minutes before slicing against the grain into thin slices.
In the meantime. Place the oil, garlic, cilantro, parsley, and lemon juice, in a blender. Blend until smooth. Season with salt and pepper to taste.
Warm the pita on both sides on a medium heat grill or in a saute pan for approximately 30 seconds per side.
Place the lettuce, tomato, onions, and sliced steak on the pita. Drizzle the sauce over top and serve with chips.