In a medium bowl, whisk together egg and water. Add flour and salt and whisk until smooth. Add greens and stir to coat.

Heat oil in a large skillet over medium heat. When hot, add greens mixture and spread until flat. Reduce heat to medium low, cover, and cook until the bottom is browned and crispy, 10 to 15 minutes.

Flip and continue to cook, uncovered, until the other side is brown and crisp.

Slice and serve with soy sauce or other condiments.