Separate the egg to yolk and whit egg. Put the white egg in a big bowl and put it in a freezer.
Mix A thoroughly till it gets smooth.
Take the egg white from the freezer, put pinch of salt and beat it into a hard meringue.
Put half of B(Meringue) into A(Yolk)and mix gently. Try not to destroy the meringue using a spatula scraping the bottom when you mix.
Put A(yolk) back to B(Merengue) , mix gently and thoroughly.
Put a food wrap on a container and put the mix into it. Make the surface flat using spatula (This time, I used a container which was about 17.5cm×10.16cm. ).
Set a microwave to 600w and microwave about 1 minute and half. You do not need to cover the mix by food wrap.
Check the mix after 1 minute and half. If it seems it is not done yet, add 15 sec more.
Take the cake out from the microwave, and cover it by the wrap which was in the container. Put it in a fridge.
In the mean time, you can work on the filling. Put all of D in a small bowl and microwave about 10 sec.
Beat heavy cream with row speed. When it gets little bit solid, add sugar substitute, vanilla extract and lemon juice. Beat well(As oil may separate out, do not beat too much ).
Cut and slice the berries to small pieces. I prefer making them around 1 cm (1/3 inch).
Take the cake out from the fridge and open on the food wrap which was wrapping it up. Slightly spread the D sauce on inside of the cake.
Put the whipped cream and fruits on the cake. DO NOT put anything on the edge of top and bottom.
Put the heavy cream and fruits about the height of 1.5 cm(1/2 inch) . It depends on the size of the container that you used, so imagine how much amount can be accommodated.
Using the wrap under the cake, roll it up and make one of the edges go over another one, and make the shape of the roll cake.
Push both of the sides of the cake gently to push back the cream which is trying to come out. Put back the cake in a fridge at least half an hour.
When you cut the cake, it will be easier to cut if you sharpen the knife and warm it up by hot water before cutting it.