Add the diced onion and to a large pot or dutch oven and saute with the olive oil. Saute until they start to brown, then add a splash of water to deglaze the pan. Saute an additional 2 or so minutes.
Add in the minced garlic and chopped cauliflower.
Saute for 5 minutes.
Add in all remaining ingredients (even the cashews!) but leave the lemon juice and flour out for now.
Bring to a boil, then reduce heat to low and cover. Let simmer for 20-25 minutes or until the cauliflower is soft.
Discard the bay leaves, then transfer to a high speed blender and blend until smooth. My blender holds 64 ounces which was just enough for this soup, but you may need to blend in two batches. When blending hot liquids, I suggest keeping the center part of the lid slightly ajar to allow heat to escape and start the blender on the lowest possible setting and slowly work your way up.
Blend for a full minute or until completely smooth. Taste and adjust flavors as desired. I usually add a bit more salt and pepper. If you want the soup thicker, blend in 1-2 tbsp of all purpose flour, then it will thicken up a bit when we transfer it back to the pot.
Transfer back to the pot and stir in the lemon juice.
Serve with a drizzle of extra virgin olive oil and chopped parsley. I also like adding my chickpea 'croutons,' found in my butternut squash soup post, but regular croutons are also great! Enjoy!