1. Rice can be made a day in advance. If making fresh, let it cool fully before proceeding.
2. Heat one tablespoon oil in a skillet over medium heat. Add the onion and sauté until golden.
3. Beat egg in a medium bowl, then add zucchini, sauteed onions, salt, and pepper. Mix well.
4. Heat remaining one to two tablespoons oil in a skillet over medium heat. Form patties by hand and carefully fry for five minutes on each side, until golden and crispy. Cool on a rack or paper towel-lined plate. Serve warm. If making in advance, refrigerate for up to three days and gently reheat before serving. Garnish with chopped chives.