Clear cauliflower and blue cheese soup - how to get it clear

If it is clear, it must be broth-based, with the cauliflower being reserved for another purpose, I would assume that a light sprinkling of perhaps less cooked cauliflower is used (rather than the cauliflower used for the broth) so that it retains its shape while sprinkled in the soup.

There are a few methods for clarifying. 1. Use the classic technique for making a consomme, which employs an egg white "raft" that captures impurities. 2. Agar clarification. See: http://www.cookingissues.com/2009/07/14/agar-clarification-made-stupid-simple-best-technique-yet/ ..., and 3. A centrifuge (an expensive proposition, but the most effective).

I've had great success with agar clarification on all sorts of things. Basically, you gel the product, then stir to break up, then strain. Of course if you start with a very thick soup, this will take some time, you may want to do a strain step first.

In addition to the 3 methods which MoscafJ points out, there is another one which is a particular favourite of Heston. I've used it a couple of times, and whilst its quite time consuming, it is very effective.

Make your broth in the usual way - I would include the cheese as there's no opportunity really to add it later. Once its cooled freeze it in a container which will fit into your colander. Line your colander with two layers of muslin, place the frozen block of soup on top of the muslin. Place the colander, muslin and soup construction on top a bowl and put the whole lot in the fridge. It will gradually defrost (takes 3-4 days) and you'll be left with a clear but flavourful broth in the bowl.

One of the downsides of this technique is that you'll loose all the gelatine from the solution. This can make the soup feel rather thin - I've added a couple of sheet gelatines before to improve the mouth feel. In your case as you're predominantly vegetable based there is unlikely to be much gelatine anyway - so you may well be OK without.

There's an article (and a video) about freeze filtration here:

http://fromcooktotrainedchefandbeyond.blogspot.co.uk/2010/01/clarifying-stock-icegelatin-filtration.html

I would suggest making a sort of consomme by making a broth and then passing it through a muslin or cheesecloth. Pour the majority of the liquid through then hang the solid mass over the bowl to allow the rest to drip out.

The tricky bit is the cheese. You might try adding it to the main broth, or adding it before the drip through stage to see if it flavours the liquid.