It is my mom recipes. She got this recipe from her mom, that means it is vey old recipe. 

Whisk the egg whites in a clean bowl until very stiff.

Whisk the yolk with sugar in a seperate bowl.

When the yolks are fluffy add lemon juice and zest, slowly.

Mix together egg whites and yolks, very lowly. Add gelatin, gently stir.

Put the desserd into decorative dishes, and leave for a hour in the fridge until set.

It is so yummy