Remove the stem and leaves from the cauliflower, give it a good rinse under cold water, pat dry and cut into florets. Peel and dice the onion as well as the garlic cloves.
Heat the olive oil in a large pot on medium heat and put in the onion. Sauté for about a minute, stirring occasionally, and add the cauliflower florets, garlic and spices. Sauté for another minute and add the vegetable broth.
Bring to a boil, reduce heat to low and simmer for about 15-20 minutes until the cauliflower is tender. Meanwhile, peel and cut the chorizo into thin slices. Put 1/2 tsp olive oil in a pan on medium to high heat and roast the chorizo chips until crispy.
Take the soup off the heat and blend with an immersion blender directly in the pot or transfer to a blender and blend until smooth. Top with the chorizo chips and infused olive oil from the pan.