Roughly chop pandan leaves. In a blender, add chopped pandan leaves and water. Blend on high speed until pandan leaves completely blended, approximately 1 to 2 minutes.
1.5 oz pandan leaves, ½ c water
Use a sieve and strain the liquid. Use a spoon and press as much water as possible from pandan's leftover pulp. Keep the liquid and pulp separately.
Bloom gelatin sheets in ice-cold water.
7 sheet gelatin
Combine cream, milk, sugar, and pandan juice in a medium saucepan. Put pandan leftover pulp in a cooking sachet bag or tightly in a coffee filter (this step is optional).
2 c heavy cream, 1 c milk, 3 oz sugar
Heat the pan on medium-high heat. Stir occasionally until sugar dissolves completely and the mixture starts to simmer.
Do not let the mixture boil, or it will be separated. Discard the pandan pulp.
Squeeze excess water from the gelatin sheet, then dissolve it in the mixture. Stir the mixture until all the gelatin sheets dissolved completely. Take the pan off the stove immediately.
Lightly spray cooking oil inside the molds.
Strain the mixture through a fine sieve mesh, then spoon it into molds. Let the panna cotta cool down at room temperature for 30 minutes. Then, put them into the fridge to set for for at least 6 hours, uncover or partially cover.
When the panna cotta is wholly set, wrap it tightly with plastic wrap. The panna cotta can be kept under refrigeration for up to 4 days.