Pour the frozen currants into a saucepan and warm them up a little, pour sugar in and cook puree until it becomes thick, in the process squeeze the berries a little.
Cool mashed potatoes and grind through sated or cheesecloth. Add the bun to it and beat with a mixer for 2 minutes.
Aga agar mix with water in a small saucepan. Put on the fire and cook constantly stirring until the agar turns into a gel. Then add sugar and boil the syrup. When thick foam appears, cook for 4 minutes, or check the readiness by leaning the spoon against a clean surface of the pan - the finished syrup should be pulled.
Beat the mashed potatoes with protein and pour the syrup without stopping whipping. When add all the syrup, beat for a few more minutes.
Transfer the mass to a pastry bag and drop the marshmallows on a flat surface covered with parchment.
Dry the marshmallows at room temperature without covering for 8-12 hours. It is not advisable that the temperature be below 20 degrees. Also, the drying time of marshmallows will depend on the humidity in the room.
Sprinkle the finished marshmallows with powdered sugar on top, separate from the parchment and combine the two halves together.