Puree fresh or defrosted frozen mango.
When the mango is pureed, set aside 1/2 cup for the coulis.
Crush the green cardamom pods in a mortar and pestle.
Remove the seeds and throw the pods away. Crush the seeds and grind them up.
Pour 1 and 1/2 cups of whipping cream into a small pot.
Sprinkle the gelatine or agar agar oven the cream in the pot.
Let the gelatine "bloom" on the cream. This takes between 1 and 2 minutes. When the surface of the cream becomes wrinkled and puffy, the gelatine has "bloomed" and is ready to use.
Whisk the gelatine into the whipping cream so that it's blended.
Add in the ground up cardamom seeds.
If you are using any sugar, now is the time to add it in. (This will depend on the sweetness of the mango you are adding later. My mango puree was very sweet so I didn't feel it needed any sugar, this is a matter of taste.)
Warm the milk or cream, (sugar if you're using it) and gelatine so that everything is dissolved. DO NOT BOIL. Take a bit of the mixture and rub it between your fingers. If there is no graininess then all is good and the gelatine is thoroughly dissolved.
When the mixture is warm, mix in 1 and 1/2 cups of mango puree.
Pour the mango panna cotta mixture into 5 small ramekins and pop them into the fridge to chill for about 2 hours.
Thoroughly puree the extra half cup of mango so that it's very very smooth and set it aside in the fridge to chill. This is the coulis.
You can serve these right out of the ramekins or unmold them easily by running a sharp knife around the rim, then dipping the bottom of the ramekin briefly into a bowl of hot water. Unmold them onto a dessert plate.
Decorate them with a bit of the mango coulis, top with a shard of Salted Pistachio Brittle.