For the plum pancakes, whisk eggs, milk, mineral water, flour, half of the honey and salt to a smooth pancake batter.
Allow to swell for half an hour. In the meantime, wash, clean and pit the plums and cut them into wedges.
Melt the butter in a pan, add the dough in portions to the pan using a ladle and swirl to distribute evenly.
Immediately and before the batter thickens in the pan, spread a handful of plum wedges evenly on top.
When the underside is harder and golden brown, flip the pancake. Serve the plum pancakes drizzled with the remaining honey.