Place sieve, lined with damp paper towel or damp cheesecloth, into a bowl. Pour plain yogurt into sieve. Cover with plastic wrap. Put into refrigerator to drain overnight.
In a medium-sized mixing bowl, stir together drained yogurt, seasoning salt, garlic, dill weed and onion powder. Mix until well blended.
Transfer into plastic container with tight fitting lid. Can be stored in the refrigerator for up to one week.
Fresh mozzarella is best enjoyed, well, fresh, but can be wrapped tightly in cling film and stored up to 1 week in the refrigerator or frozen up to 3 months.