First, soak cashews overnight or simmer in boiling water for 15 minutes. Mix the nuts with water, then add the aquafaba and beat at high speed until frothy. The mixture should have a smooth consistency. Pass through a sieve to get rid of small bits of nut and transfer to the blender again. Add starch, carrageenan, lactic acid, nutritional yeast, and salt. The amount of the latter may vary depending on how salty the aquafaba originally was. Mix the ingredients, then pour in the coconut oil and mix quickly again (if using solid oil, dissolve it first, then let it cool to room temperature). The mixture should be smooth and slightly thick.
Pour the mixture into a saucepan and put on medium heat, stirring constantly. Gradually, the mixture will turn shiny and smooth, like melted cheese. When it starts to bubble around the edge and thickens, remove the pan from the heat. Pour into a mold and refrigerate for a few hours to harden the mixture. Use with any dish like regular mozzarella.