Trim and wash the green beans. Dry thoroughly with a towel.
In a large bowl, whisk together the flour, egg and 1/2 c. water. Add more water as needed so that the batter is smooth but still thick and not runny. Stir in sugar, salt and optional 5 spice powder. Add the green beans to the batter and stir to coat.
In a large skillet, heat about 1 1/2 inches oil over medium heat until hot. Add a few handful of beans to the oil at a time. Cook in the oil until lightly browned and crisped. Drain on paper towel.
Notes
If you are not going to be eating the green beans right away, keep in a warm oven. They’ll stay crispy and as good as fresh that way.