A key ingredient in Greek as well as Italian cuisine, you'll find the best varieties are often identified as Greek or Italian oregano. Oregano is a perennial plant and should come back every year, and it prefers well-drained soil (no soaking!) Unlike many herbs, it has more flavor dry than it does fresh. When using it fresh, add it to your dish immediately before serving (not hours before,) but if you want an easy way to dry it and don't have a food dehydrator, just leave it in the oven with the interior light on for a while.