To a large mixing bowl, add the steak, potatoes, oil, butter, salt, pepper, garlic, onion powder, oregano, parsley, dried thyme, and rosemary leaves. Using a spatula, stir gently until everything is evenly combined and coated.
2 1/2 lbs sirloin steak, 1 lb baby potatoes, 2 tbsp olive oil, 2 tbsp butter, salt & pepper, 2 tbsp minced garlic, 1 tsp onion powder, 1 tsp dried oregano, 1 tsp dried parsley, 1 tsp dried thyme, pinch fresh rosemary leaves