Pour the chickpea liquid into the bowl of a stand mixer. Use the whisk attachment to beat on high until soft peaks form. Slowly add the sugar and then the cream of tartar while the mixer is running. Continue to whisk until stiff peaks form.
Place the chocolate in a large glass bowl and melt in the microwave or over a double boiler. Allow the chocolate to cool slightly, then fold it into the whipped chickpea meringue.
Place the coconut cream in a mixing bowl and whisk, continuing until stiff peaks form.
Stir 1/3 of the coconut cream into the chocolate mixture, then fold in the remaining.
Divide into four 1-cup containers and refrigerate for at least 2 hours. Top with chopped pistachios and orange zest before serving.