Combine cornstarch with 2 tbsp of coconut milk in a small bowl. Whisk until lump-free.
Transfer cornstarch mixture and remaining coconut milk onto a saucepan and heat over medium high. Use a thermometer to read the mixture until it reaches 180°F. Stir occasionally for 5-10 minutes.
Let milk cool down until 110°F. This will allow fermentation.
Once cool, combine yogurt started with a tablespoon of milk and stir until lump-free. Add to coconut milk mixture and stir well.
Transfer the mixture to a glass jar and leave in a draft-free area for 12 hours.
Once the incubation period is over, put the jar into the fridge and let it sit for another 6 hours so the mixture thickens. Serve.
