Cut off the green tops of the leeks and compost them.

Clean the leeks by slicing them lengthwise, stopping at the root end. Hold upside down under running water and open up each layer of leek, washing all the dirt down the drain. Shake dry.

Roughly chop the leeks. Peel and roughly chop the onion and garlic. (Omit onion for migraine diet.)

Heat the olive oil in a large heavy-bottomed soup pot over medium-high heat. Add the leeks, onions, and garlic, stirring. Cook for about 8 minutes until softened and reduced in size by nearly half. Add the salt (if using) to season while sautéeing.

When they are just starting to brown, add the white wine and cook for 2-3 minutes more. (Omit wine for migraine diet.)

Scrub the parsnips and trim both ends. Cut into large chunks. Add to the pot with the sage, nutmeg, and white pepper. Cook for about 3 more minutes, stirring to mix.

Add the broth plus 2 C. (500 ml) filtered water. Stir to combine. Cover and bring just to a boil, then turn down the heat to a gentle simmer and cook for 30-45 minutes, until the parsnips are very tender.

Puree in batches in the blender until completely smooth.