Bring a large pot of water to a boil.

Add ½ tablespoon of salt, and leeks.

Boil for ten minutes. Remove leeks.

Add broccoli and remaining salt to water.

Boil broccoli, just until tender, about 1 to 2 minutes. Remove broccoli from water, reserving the water that the broccoli and leeks boiled in.

Add herbs, if using, and boil for thirty seconds.

Place all vegetables in a blender. Add 3 cups of reserved water and blend until smooth. Add additional water to achieve desired consistency.

Garnish with shredded Parmesan cheese, if desired.