Broccoli-Cheese Soup

I was a little skeptical of this soup, but curious. I associate broccoli-cheese soup with a bright orange soup and florets of broccoli. It's anything but healthy, but it's delicious. This on the other hand uses no milk or cream and a minimal amount of cheese, yet the taste is still amazingly flavourful and it's cheesy enough to satisfy my need for regular cheese. The colour is still a bit shocking ...

but with that colour, you can pretend the soup is even healthier than it is!

Broccoli-Cheese Soup (from Cook's Illustrated)

Ingredients
2 tbsp unsalted butter
1 kg broccoli, florets roughly chopped and stems trimmed, peeled, and chopped
1 medium onion, chopped
2 medium garlic cloves, minced
1 1/2 tsp dry mustard powder
pinch cayenne pepper
salt
3 - 4 cups water
1/4 tsp baking soda
2 cups chicken broth
60g baby spinach (2 cups)
85g sharp cheddar cheese, shredded
40g Parmesan cheese, grated
ground black pepper

1. Heat butter in a large Dutch oven over medium high heat.
2. Add broccoli, onion, garlic, dry mustard, cayenne, and 1 tsp salt. Cook stirring frequently until fragrant, about 6 minutes.
3. Add 1 cup water and baking soda. Bring to a simmer, cover, and cook until broccoli is soft, about 20 minutes. Stir once during cooking.
4. Add broth and 2 cups water and increase heat to medium-high.
5. When the mixture begins to simmer, stir in spinach and cook until wilted, about 1 minute.
6. Add cheese. Blend until smooth with an immersion blender.
7. Adjust consistency of soup with up to 1 cup water (I didn't need to). Season to taste with salt and pepper.