I don't know why but I've only recently discovered how to properly clean a cauliflower head without making a huge mess of it and while it's probably known to most people, here's the trick anyway:
Clean of the green parts and what you can get of the stem and then cut the head in four pieces, which then makes it really easy to get out the remaining parts of the stem and have your cauliflower fall into the florets you want.
On to the soup!
1 Cauliflower head
3 Cloves of garlic (I used 3 cloves but you can use less if you prefer)
1 tsp Curry powder
1 tsp Turmeric
1 tsp Coriander
1 tsp Cayenne pepper
(I'm not completely sure on how much I used of the spices so feel free to vary or add or leave out some)
Vegetable stock (I used 700ml but I recommend a bit more depending on the amount of vegetables)
Soy milk (I have no idea how much I used, I just went by look and feel of the soup
Salt to taste
I roasted the cauliflower and the garlic with some olive oil, lots of garlic for me because one can never have enough garlic!
While the cauliflower was roasting, I sauteed the onions...
...and decided I wanted some potatoes in my soup as well so I put them in the oven with the cauliflower. I highly recommend deciding about the potatoes before and put them in right at the beginning.
I added the spices, roasted vegetables and vegetable stock to the onions.
I let all of that simmer for a while because the potatoes still had to cook through completely and once it was all done I mashed the vegetables and added some soy milk to make my soup a bit more creamier. I served it with some flat bread I roasted in the oven with a bit of olive oil sprinkled on it and garam masala on top, which worked really well with the already spiced soup.