Hot & Sour Soup Noodles (Inspired by Ottolenghi)

Got the January blues? Then this hot & sour soup is just the thing to banish them away. It won't transport you to south-east Asia but it will make you feel better. The original recipe is by Yotam Ottolenghi and is taken from his Guardian column.

Hot & Sour Soup Recipe (serves 4 as a main/up to 8 as a starter)
My version has some changes due to personal taste, and the fact that it was a royal pain in the arse tracking down all the ingredients. I gave up looking for Thai basil after the third shop I visited didn't have any (despite seemingly stocking every other Thai herb going). I didn't even bother looking for coriander root and I forgot to buy the prunes.

3 medium onions, peeled and cut into large pieces
3 medium carrots, peeled and cut into large pieces

6 sticks of celery, roughly chopped (I used more cos I bloody hate celery, and have no other use for it)
6 garlic cloves, peeled (I used more cos the cloves were small)
3 knobs of ginger, peeled and roughly chopped (original recipe calls for 75g but who in their right mind weighs ginger?)
Groundnut oil

3 lemongrass stalks, roughly chopped (I used 2, as that's all I bought)

3 red chillies, roughly chopped (add more if you like it hot)
6 star anise (I used an extra star or two to finish off a jar)

1 cinnamon stick (not in original recipe but it goes well with star anise)
2 tbsp soy sauce

6 lime leaves

Coriander leaves (I used a 20g bag)
Juice of 2 limes

4 tsp tamarind paste

Salt (optional - I didn't add any)
Sesame oil, to finish (optional - I didn't bother)

Toppings
You can finish off the soup with your favourite toppings but for the pictured version, I went with:

Fresh Ho Fun rice noodles
Fish balls
Enoki mushrooms
Baby leaf spinach

Fresh Ho Fun rice noodles (河粉) can be found in Chinese supermarkets but if you can't track them down then dried rice noodles will do. In fact, you can use just about any type of noodle but there is something especially satisfying about using silky smooth rice noodles in this dish.

Other suggestions for toppings include different varieties of mushrooms, beansprouts, green beans, pak choi, poached egg, prawns, or anything else that takes your fancy.

Method
1. In a large pan, char the onion, carrot, celery, garlic and ginger in a tiny amount of oil for about five minutes.

2. Add 2.25 litres (4 pints) of water, the lemongrass, chillies, star anise, cinnamon, soy sauce, lime leaves and half the coriander. Cook on a low simmer for an hour to infuse.

3. Strain the stock, return to the pan and bring to a very low simmer.

4. If any of the toppings e.g. fish balls, need to be heated through, then put them in the soup now.

5. In a separate pan, cook the noodles, drain then place in bowls.

6. Add the tamarind paste and lime juice to the soup, and heat through for a minute.

7. Add any toppings that don't really need cooking e.g. enoki mushrooms and baby leaf spinach, to the soup.

8. Taste, adjust the seasoning as needed and ladle into the waiting bowls of noodles.

9. Garnish with remaining coriander (and Thai basil if you can find it), and add a couple of drops of sesame oil, if you fancy.