Crepe batter: Sift the flour into a bowl, add salt, eggs and 5 tablespoons milk. Gradually adding the rest of the milk, mix with a whisk or beater until the batter is smooth. Cover the bowl with a cloth and let rest for 30 minutes. Fry the crepes in a well-heated small pan, each with 1 teaspoon oil.
Plums: Wash, dry, cut in half and remove the pit. Place in a pot, add sugar, vanilla sugar or vanilla extract, pour in white wine or water. Bring to a boil, stirring occasionally. Cook for another about 3 minutes, until the plums release their juice and soften. Strain in a sieve. Reduce the remaining plum - wine juice by cooking it for about 5 minutes, or until it reaches the desired thickness. Layer the crepes with plums, fold into triangles and arrange in an ovenproof dish brushed with 1 teaspoon butter. Finely chop the remaining butter and distribute it over the crepes. Preheat the oven to 200 degrees.
Meringue: Whip the egg whites with salt and lemon juice or wine vinegar into stiff peaks. At the end of whisking, add the sugar one tablespoon at a time, continuing to whip. Whip for another about 3 minutes until the foam is glossy. Spread the meringue over the crepes and place in the preheated oven. Bake for about 12 - 15 minutes, until the meringue is lightly golden. Pour the thick plum - wine sauce over the crepes, decorate with fresh mint or lemon balm.
