If using yogurt, strain it in a clean cloth bag for a few hours to separate yogurt water.
Pour yogurt water (or fresh milk) into a large pot. Heat gently, stirring to dissolve particles.
Bring to a boil, then lower heat and simmer. Stir occasionally to avoid burning.
Continue simmering until the liquid thickens (this may take several hours).
Transfer the thickened mixture into trays or bowls. Let it cool and harden.
Cut into pieces and place in a basket or on a cloth. Leave in a cool, shaded place to dry for 2–3 days until firm and dark brown.
Store in an airtight container and enjoy as a snack or seasoning.