Preheat oven to 170 F. Place parsley on a baking sheet, careful not to overlap any of the leaves. You will be drying the entire parsley stem and leaf, I find this method less time consuming than removing individual leaves.
Put in the oven for 20 minutes, checking it reguarly to make sure it does not burn. After 20 minutes, check the leaves to see if they are dry and crumble easily. If they are not dried yet, add 5 minutes. Check again. Repeat until leaves are completely dry. Remove from oven.
Place stem over bowl and gently crumble the leaves with your fingers. Continue until all the parsley leaves are crumbled.
Store dried parsley in glass jars in a cool, dry cabinet.