I get these confused so I am using both names. My mother used to make this. It is very old fashioned and quite nice. It's made by "floating" mounds made of airy lemon and egg white in a pool of custard sauce.
Make a batch of custard sauce and chill.
Mix one envelope of gelatin (1 tablespoon) with
1 cup sugar and a pinch of salt.
1 1/2 cups boiling water.
Stir until gelatin is dissolved.
Add 1/4 cup lemon juice.
Chill until thick but not fully set. Add 3 egg whites and beat until thick enough to hold its shape. Mold in ramekins or small fruit dishes until firm.
Unmold into a large bowl of the custard sauce.