Add the nuts into the bowl of a food processor and process into a thick, doughy sort of paste. This can take as long as 10 minutes, so be patient and don’t rush this step, or gritty ice cream may result. 2. Once the nuts seem to have surrendered their natural oils and are well pulverized, stop the machine. Drain excess liquid from the tofu and add it to the pistachios. Blend the mixture well, being sure to stop and scrape down the sides periodically, until the mixture is completely smooth. 3. Add the avocado, lemon juice, non-dairy milk, agave, vanilla, and salt to the food processorand blend until all of the ingredients are fully incorporated. Pour the mixture into your ice cream maker and freeze according to the manufacturer’s instructions. In the last 5 minutes of freezing, toss in the chopped pistachios.