Mix gelatin and water in a saucepan until gelatin is moist. Heat on low heat until mixture becomes liquid. Set aside.
Heat heavy cream, milk, and sugar in a large saucepan on medium heat. When you begin to see small bubbles just begin to form, turn off the heat.
Add liquid gelatin mixture into milk mixture. Whisk thoroughly until well incorporated.
Then whisk in passion fruit juice into milk mixture. You will see the milk begin to curdle. Continue whisking vigorously until the mixture is smooth again.
Place mixture evenly into 8 ramekins. Cover with foil and place in the refrigerator to set for 8 hours, or overnight.