Curried Cauliflower Soup

I had a potluck to go to and decided to make a soup. I'm a big fan of thicker pureed soups and I wanted to use a head of cauliflower I had in the fridge; so this is what I came up with.

1 tablespoon whole coriander toasted and freshly ground
1 tablespoon whole cumin toasted and freshly ground
1 teaspoon of turmeric
1 teaspoon hot red pepper or more
2 tablespoons of garlic, minced
1 tablespoon of ginger, minced
1 large onion, small dice
1 large celery root, cubed
1 large head of cauliflower, broken into florets
2 medium potatoes, cubed
1 quart vegetable stock
3–4 cups of water
Salt
Olive oil (I use Whole Foods brand EVOO for almost everything except for deep frying)
1 cup of heavy cream

Toss cauliflower florets with a bit of olive oil and salt and roast in a 400° oven until browned.

Sweat Onion until translucent, heavily salt to help the process along. Add all of the spices and stir over medium high heat. You want to release the oils in the spices and you will have a sticky mess in the bottom of the pot. Add celery root, garlic, ginger and potatoes. Add a little water if necessary to scrape up any browned bits on the bottom of pot and saute until everything starts to just take on a bit of color. Add water, stock and roasted cauliflower and BRB then RTS (Bring to Boil, Reduce to Simmer)

Simmer until the veggies are fork tender then shut off heat and puree with an immersion blender (You can buy an immersion blender at Bed Bath and Beyond for around $50 bucks and it's money well spent!).
Blend to a smooth consistency and then add the heavy cream. Ladle into bowls and enjoy.