Ottolenghi's Garlic Soup with Harissa

A few days ago, I came across an article in the New York Times Dining section featuring Yotam Ottolenghi. A light went off in my head. D'oh! I had forgotten to post his recipe I made last week.  
Garlic soup with harissa. Yum. Yum. Yum. This recipe uses 25 medium cloves of garlic, but don't be scared. You can still snuggle up to that special someone (without embarassment) or have a close face-to-face conversation. Well, maybe after a palette cleanser like sorbet. In general, when garlic is cooked like this, the subtle sweet flavor remains while the harsher 'garliciness' evaporates substantially.   
Harissa, a Tunisian hot chili sauce, is made from peppers and spices such as such as garlic paste, coriander, red chili powder, coriander and caraway. It's very popular in Algeria and, according to my research, is making inroads in Egypt and throughout the Gulf States. Harissa is also the perfect condiment to this soup. 
Since I've been cooking up a storm recently, I decided to buy a pre-made harissa. I know this is a shortcut, but I'm lucky to live near a provisions shop that carries harissa by the gallon...and it tastes great. For those of you who don't have harissa-access, I've included the recipe below. 
The soup is pretty light and it's not thick at all. It's somewhere between a broth and puree. I served it in a shallow bowl, with a swirl of harissa and a nice dollop of Greek yogurt.  Enjoy! 

Garlic Soup and Harissa (Courtesy of Plenty: Vibrant Recipes from London's Ottolenghi)
Serves 4.
The soup:
3 tbsp butter
2 tbsp olive oil 
4 medium shallots, finely chopped 
3 celery sticks, finely diced 
25 garlic cloves (medium size), finely sliced 
2 tsp chopped fresh ginger
1 tsp fresh thyme, finely chopped
1/2 tsp coarse sea salt 
1 cup white wine 
1 generous pinch saffron strands 
4 bay leaves 
1 litre good-quality liquid vegetable stock (not cubes) 
4 tbsp parsley, roughly chopped 
Fresh cilantro, roughly chopped  (optional)
Greek yogurt (optional)
Gently fry shallots and celery until soft and translucent (about 10 minutes). Add the garlic and cook for five minutes more.  Stir in ginger and thyme, add salt, pour in the wine and leave to bubble for a few minutes. Add the saffron, bay leaves and stock, and simmer for 10 minutes. Remove the bay leaves, add the parsley and blitz with a hand-held liquidiser (immersion blender). Do not over-process - keep some texture.
The harissa:
1 red pepper 
1/4 tsp coriander seeds 
1/4 tsp cumin seeds
1/4 tsp caraway seeds
1/2 tbsp olive oil 
1 small red onion, roughly chopped 
3 garlic cloves, roughly chopped 
2 medium-hot fresh red chillies, seeded and roughly chopped 
1/2 tbsp tomato paste 
2 tbsp lemon juice 
2 to 3 tsp coarse sea salt
Put the pepper under a very hot grill until blackened (15-20 minutes). Transfer to a bowl, cover with saran wrap (or "clingfilm" as the British say), leave to cool.  Then peel and discard the skin and seeds. Place a dry frying pan on a low heat and lightly dry toast the coriander, cumin and caraway for two minutes. Transfer to a mortar and grind to a powder. Heat the oil in a frying pan and fry the onion, garlic and chillies over medium heat until dark and smoky - six to eight minutes.  Cool slightly, then tip into a blender or food processor.  Add the remaining harissa ingredients, including the grilled pepper and ground spices, and blitz together to make a paste.  Set aside until you are ready to use it.