Heat evoo in a medium pot over medium-high heat Add leeks and sauté for about 5 minutes until they soften. 

Add garlic and parsnips and cook another 5 minutes. Add parsley, wine, and water and simmer, covered, until parsley is wilted.

Puree soup in a blender, or with an immersion blender, until smooth. If desired, pour through a fine-mesh sieve into cleaned saucepan, pressing hard on solids, then discarding them. Reheat if necessary.