Peel and finely chop the onion. Pull 2 garlic cloves from the bulb (save the rest for your other soup recipe), then peel and crush them. Pop a large pan on a low heat and add ½ tbsp olive oil, the onion and a pinch of salt and pepper. Fry for 8-10 mins, stirring occasionally, till the onion is soft but not coloured. If it starts to brown, turn the heat down, if you can, and add a splash of water.
While the onion cooks, fill and boil your kettle. Fill a large bowl with cold water. Rinse the Jerusalem artichokes then peel them, dropping each peeled artichoke into the bowl as you go. This stops them turning brown. Remove 1 artichoke at a time from the water and roughly chop it, popping it back into the bowl, repeating until you’ve prepared them all. Peel and chop the potato into small chunks.
When the onion has cooked for 8 mins, add the garlic and 2 tsp mild curry powder to the pan. Stir for 1 min. Drain the artichokes and add them to the pan, along with the chopped potato. Pour in 800ml hot water from the kettle. Pop a lid on and simmer for 15 mins till the veg are soft.
When the veg are soft use a hand-held blender to whizz the soup in the pan till smooth and creamy. Pour in half the carton of single cream and blitz again. Taste and add more salt or pepper if you think it needs it. No stick blender? You can pour the soup into a blender, add the cream and blitz.
Ladle the soup into a couple of warm bowls and top it with the flaked almonds to serve.