Melt the sugar in an 8 inch cake pan (preferably a coated one). To do this, put the pan directly over a medium heat burner stirring continually (You can also do this in a sauce pan and pout into the cake pan) After a few minutes the sugar will actually liquify and become a dark golden-brown or caramel color. Tip the pan to make the liquid cover the bottom evenly and begin to go up the sides of it. Place the pan in the freezer.
Preheat the oven to 350 degrees and place inside it a roasting pan (big enough to hold the cake pan) half filled with water.
Pour the condensed milk into a large bowl. Blend the water, cheese, eggs, vanilla and salt in a blender or food processor until very smooth. Whisk this into the bowl with the condensed milk. Pour it all through a wire sieve into the cake pan you have removed from the freezer.
Carefully lower the cake pan into the pan of simmering water. Bake for 50 minute Check for doneness. Remove the flan from the oven and let it rest at room temp for an hour. Then place in fridge overnight and just before serving invert and unmold it. The lovely caramel you made will now be on top.