Soak the cashews and almonds overnight. Drain and transfer to a high-speed blender. Add the water and blend on high for about 30 seconds.

Transfer the cashew and almond milk to a nut milk bag and squeeze it over a large bowl to strain the milk. Try straining as much milk as possible. Discard the pulp or use in cookies, cakes, etc.

Dissolve the cornstarch in 3 tbsp of the cashew/almond milk. Add it back to the milk.

Transfer the cashew/almond milk to a medium sauce pan, add the sugar, and heat over medium heat. Whisk constantly until it comes to a boil and starts to thicken. As soon as it as thickened, remove from heat, pour into a small glass bowl and cover with plastic film to touch (to prevent a skin from forming on top). Let it cool for about 1 hour, or until it's at room temperature.

Add the teaspoon of non-dairy yogurt and stir using a wooden spoon to mix with the milk. Cover again with plastic film to touch.

If using an Instant Pot: Place 1 cup of water in the pot. Add the steam rack and place the bowl of yogurt on top. Close the lid and set on Yogurt mode for 7 hours for a mild yogurt.

If using a Yogurt Maker: Divide the yogurt into small jars. Set the maker for 7 hours.

If using an Oven: Turn on the oven and set it to the lowest temperature (mine is 50°C). Preheat for about 20 minutes. Next, turn it off but leave the light on. Place your bowl of yogurt in the oven and let it incubate for 7-8 hours with the light on.

Once your yogurt is ready, refrigerate for at least 3 hours, or until cold before enjoying. Yogurt will keep for up to 5 days in the refrigerator.