Beat together the eggs, corn flour and agave syrup. Bring the milk, orange zest and saffron to boil just under boiling point.
Pour the milk slowly into the egg mixture whisking continuously. Return the mixture to the pan again and bring it to heat, stirring continuously under medium to low heat until the mixture coats the back of the spoon.
Remove it from heat, cover the top of the mixture with a cling film and let it cool down.
To prepare the caramel, mix the water and sugar together in a pan and bring it to heat. Keep the flame in low until the sugar is completely dissolved in water.
Once the sugar is dissolved bring it boil, when the sugar turns golden caramel in colour immediately take it off from heat and add the orange juice to stop cooking.
Take four ramekins and quickly pour the caramel in the four ramekins and swirl it around.
Preheat the oven to 180 degree Celsius. Pour the custard mixture into the caramel coated ramekins. Bake it in the preheated oven for 25 to 30 minutes or until the custard is completely set.