Onion Fluid Gel

Motivation
I remembered reading about a onion gel somewhere.  After a bit of investigation I tracked it down to Heston Blumenthal's Fat Duck Cookbook.  For a Fat Duck recipe, the gel is pretty simple.

Ingredients
30g Butter
250g Onions, finely sliced
1g Sprig of Thyme
200g Milk
95g Whipping Cream
150 Beef Stock (or Chicken)
2.7g Gellan F

Method
Melt butter in sauce pan, add onions and thyme and sweat for about 5 minutes until onions are soft and translucent.  Add milk, cream, and stock and simmer another 5 minutes.  Remove thyme and pulse a few times with an immersion blender.  Strain through a fine sieve and add salt to taste (if needed).

Weigh out 400g of the onion milk.  Place in a sauce pan, add gellan, and heat.  Whisk often to dissolve gellan. When onion milk reaches about 80 degrees C (on the IR thermometer) remove from heat, pour into another container and place container on ice.  Blitz with immersion blender everyone so often until mixture is cool.

Keep refrigerated and deploy as called for.   Gel should be heat stable if you want to rewarm it.