The Courthouse's Roasted Cauliflower and Garlic Soup

I've been wanting to make a soup for some time now, and when I came across this recipe on the Courtyard Restaurant's website, I figured this past weekend was as good a time as any. I was pleased with the results, I made a very creamy and flavourful soup. Because the recipe made more than what my family and I were willing to eat, I've pared down the recipe, all measurements are assumptions or approximations.

Ingredients
1 bulb garlic, roasted
1.25 heads cauliflower, roasted
2 onions roughly chopped
1.5 stalks celery roughly chopped
1.5 cloves of garlic roughly chopped
0.25 cup butter
salt and pepper to taste
1 bay leaf
4 cups water
1/4 L heavy cream

1. Add cauliflower and half of the onions to a large bowl.  Season with salt and pepper and toss with vegetable oil.  Spread evenly on parchment lined baking sheet and roast in a 450 degree oven until golden brown.  Rotate/toss cauliflower as necessary to prevent uneven browning and burning.
2. Place a head of garlic with its top cut off on a baking sheet and drizzle with olive oil.  Cover with tinfoil, roast in 450 degree oven for approximately 40 minutes.
3. In a large pot add butter, celery, garlic, and the remaining onions until they become translucent.  Add the roasted cauliflower, onions and garlic to the pot, add water, cream and bay leaf.  Bring to a boil, then reduce heat to simmer.  Cook until the vegetables are very tender. 
4. Use an immersion blender to puree, then pass through a sieve, or use a blender and blend in small batches.  Return the soup to the large pot and heat to desired temperature. 

Here's how it turned out:

Feel free to leave comments, as it's the only way I'll learn.