Pour ¾ cup cream into a small bowl. Whisk in tapioca starch then set aside. In a saucepan, whisk together the heavy cream, milk, sugar, and brown rice syrup. Place over medium-high heat and whisk continuously until the mixture comes to a rolling boil. Reduce heat to medium-low and continue cooking the mixture at a soft boil for an additional 5 minutes, whisking each minute.

Next, while whisking the hot cream and milk mixture, pour the cream and tapioca mixture into the saucepan, whisk continuously. The mixture will thicken almost immediately.

Remove from heat and add the vanilla to the ice cream base mixture. Zest the lime directly into the saucepan then stir in with the chopped cilantro and vanilla. Cover with plastic wrap and refrigerate to steep and chill, 2 to 4 hours or overnight.

Strain the mixture, removing the cilantro and lime zest. If bits of cilantro and lime zest slip through, don't despair. It only adds to the aesthetic of the ice cream. Pour into a prepared ice cream maker and churn until thickened to a soft-serve consistency, 15 to 20 minutes. With a spatula, transfer the ice cream to a freezer-safe container and freeze at least 2 hours or until hard before serving.

Serve garnished with a simple sprig of cilantro or a wedge of lime.