Take the reserved strawberries and dice them (this is to fold into the batter later for chunky dessert- if you don’t like, you can skip this and just blend it with the rest of them).
Take the rest of the strawberries and blend it will all the ingredients EXCEPT the egg white.
Beat the egg white till it forms stiff peaks.
Gently fold in half the strawberry purée and the diced strawberries till combined.
Pour the remaining strawberry purée in the bottom of a serving dish, layer the strawberry mousse mixture on top.