01 - In a large bowl, whisk together flour and salt. Add eggs and half the milk, whisking until smooth. Gradually incorporate remaining milk and melted butter; whisk until batter is thin and free of lumps. Let rest for 10 minutes.
02 - Warm a nonstick skillet over medium heat and lightly brush with butter.
03 - Pour approximately 1/4 cup batter into skillet, swirling to create a thin layer. Cook 1 to 2 minutes until edges lift and underside is golden, then flip and cook an additional minute.
04 - Sprinkle one quarter of cheese and ham over half the crepe. Crack an egg onto filling if desired, season with pepper and chopped chives, then fold or roll crepe to enclose filling.
05 - Cover and cook 1 to 2 more minutes until cheese melts and egg white sets while yolk remains runny. Repeat with remaining batter and fillings.
06 - Serve crepes hot, garnished with additional fresh chives.