2. Place the leche flan mixture into a ceramic bowl. Place this bowl into a second bowl of water, so that the waterline is just ABOVE the level of the leche flan.
3. Place into a pre-heated oven at 160C. Cook for 35-45 min, checking occasionally to ensure that waterline does not drop below the leche flan level.
4. Remove from oven while leche flan is still soft (it will continue to back in its own heat.)
5. Place water, sugar and lime zest into saucepan. Bring to boil, stiring constantly. When the mix starts to become a syrup, pour over leche flan.