Ohh, it’s really easy!
Cold porcelain clay recipe:
1/2 cup baking soda
1/4 cup corn starch or potato starch
2/3 cup water
Mix ingredients in pot then put on the stove on middle heat. Stir for 1-2 minutes and when you see its all solid, take it out of the pot. Put a small amount of lotion on your hand and start kneading.
The things that can be modelled from cold porcelain clays are incredible. Its possible to sculpt finer details than polymer clays. Objects dry to a light-weight, stone like texture. For example porcelain grape.