Reduce heat to medium low and add in the diced tomatoes, ½ can of water, the vegetable broth and additional water. Stir in the cauliflower, mushrooms, chickpeas and all of the seasonings from the salt to the crushed red pepper.
Stir in the parmesan cheese and reduce heat to low. Cook on low for 2-3 hours, stirring occasionally and adding salt/pepper to taste.
Before serving, stir in handfuls of baby spinach and enjoy with a dusting of parmesan cheese.
Recipe by Keys to the Cucina at http://keystothecucina.com/2015/02/18/cauliflower-soup-with-spinach-mushrooms-and-parmesan/