Put plain yogurt in some cheesecloth stretched over a bowl. Cover with plastic wrap. Let stand for a couple days. The liquid will come out into the bowl, leaving the "cheese" behind.
Notes
The yogurt cheese makes a great dessert. Mix it with some sugar and some saffron soaked in hot water or mango pulp. You can also use it for a cheesecake in place of cream cheese.
Substitutions
Milk and Soy Substitutions: Alternative dairy-free milk beverages and products will work in most recipes. Find out more about milk substitutions and soy substitutions.