Break the white chocolate into pieces, and place in a medium sized heat proof bowl. Fill a saucepan (that is the same size of the bowl) half way with water and bring to the boil.
Once boiled place the bowl of chocolate over the saucepan to create a makeshift double boiler, reduce the heat to medium and leave the chocolate to melt. (do not stir the chocolate or it will ruin).
Place the cream cheese in a medium sized bowl and proceed to whisk with a hand mixer until smooth (don't over mix) it should take less than 1 minute.
Pour and whisk in the full fat coconut milk and powdered sugar.
Pour the melted chocolate into the bowl and whisk until full combined.
Add the guava puree then whisk until the mixture is smooth.
Scoop out a few tablespoons of the cheesecake filling and stir into the agar agar mixture
Stir the agar agar mixture into the cheesecake filling using a spoon.
Pour the filling onto the base of the cheesecake.
Spoon the remaining guava puree on top of the cheesecake in blobs then use a blunt knife to marble the puree using a back and fourth/side to side motion (don't run the knife too deep, just less than an inch into the cheesecake is fine).
Carefully transfer the cheesecake into the freezer and leave to set overnight (very important).