5-6 egg yolks
6 tbsp sugar or sugar powder
0.5 tsp brandy or rum (optional, for adults)
Peel the lemon, and cut the peels into very small pieces.
Whip egg yolks and sugar until an even consistency, then add lemon peels, and whip until getting a thick, foamy consistency.
Optional: add rum or brandy, and whip for 1 more minute.
This is a very Old Russian drink for adults and kids, which increases their strength.