01 - Strain the watermelon juice through a fine mesh sieve to eliminate all pulp and seed particles, ensuring a smooth liquid base for the pudding.
02 - In a medium saucepan, combine granulated sugar and cornstarch. Whisk thoroughly to blend the dry ingredients and prevent clumping during cooking.
03 - Gradually pour the fresh watermelon juice into the saucepan while whisking continuously. Incorporate lemon zest and vanilla extract, whisking until completely smooth and lump-free.
04 - Place the saucepan over medium heat. Stir constantly with a whisk or heat-resistant spatula as the mixture begins to bubble. Continue cooking for 8 to 10 minutes until the pudding reaches a soft, velvety consistency that coats the back of a spoon.
05 - Remove the saucepan from heat. If creating the traditional appearance, gently fold dark chocolate chips into the hot pudding—they will soften and resemble watermelon seeds.
06 - Pour the warm pudding evenly into individual serving glasses or decorative molds. Allow to cool to room temperature, then transfer to refrigerator. Chill for minimum 3 hours until completely set and firm.
07 - Just before presenting, sprinkle each portion with finely chopped pistachios. Add dried rose petals and extra chocolate chips if desired for enhanced visual appeal.