Into a pan, add the water and turn on the heat. As soon as it starts to boil, turn off the heat. Pour in the packets of jelly powder and fully dissolve.
Into a blender, add the dissolved jellies, the condensed milk and the packs of table cream. Blend until combined.
Grease a ring cake tin with a drizzle of oil and spread well, then transfer the mixture from the blender to the cake tin and cover with plastic wrap. Let it chill in the fridge for 2 to 4 hours.
Note: Run a knife along the edges and center of the cake tin to make it easier to unmold.