Heat oil in a soup pot over medium heat on the stove. Add the onion and sauté about 4 to 5 minutes, until soft and translucent. Add the garlic, cumin, salt, pepper, and nutmeg, and sauté 1 minute until fragrant.
Add the remaining cauliflower florets, chickpeas, and broth. Stir to combine. Increase the heat to bring to a boil, cover, then decrease the heat to medium-low and simmer for 15 minutes, until the cauliflower is tender and easily pierced with a fork or knife.
Take off the heat. Add the non-dairy milk, nutritional yeast and hot sauce, if using. Using an immersion blender, purée the soup in the pot until silky smooth. Alternately, you can carefully transfer the soup to a blender to purée. Work in batches, if needed. Do NOT fill the blender past the max fill line!
Serve warm with garnishes, like roasted cauliflower, chopped almonds, and/or fresh chopped parsley.