Since we are frying in a tempura better, you don't need an egg. But if you do prefer to bread with panko/breadcrumbs, I would suggest dredging in one large egg first, then transitioning to your dry dredge (panko, etc.) and fry from there. Since this a a wet tempura batter, we don't need an egg! I like how light and fluffy the tempura batter gets, as it pairs nicely with this delicate flower. However, it is totally up to your preference.