Chop onion, mince garlic, chop cauliflower into florets
Zest lemon with a Microplane
In a large soup pot, heat olive oil over medium heat. Saute onion and garlic gently until soft and fragrant.
Add miso paste and stir to begin to coat onions.
Add cauliflower, lemon zest, cashews, and water. Stir to combine. Bring to a boil, then reduce to a simmer, until cauliflower is soft; about 15-20 minutes. Add additional water if necessary to keep cauliflower covered.
Remove from heat and let stand until cool enough to puree.
Puree soup in batches in a blender. (Be sure to secure the lid of the blender as steam from the soup can create pressure and pop off the lid).
Season with salt to taste and top with herbs and oil.