Fill and boil your kettle. Peel and finely chop the onion and potato. Rinse and tear the mushrooms into small pieces. Warm a large pan for 1 min. Add ½ tbsp oil and the chopped veg. Season with a pinch of salt and pepper. Sizzle over a medium heat for 5 mins, stirring often, till the veg pick up a little colour.

While the veg fry, trim the roots and any ragged greens off the spring onions. Thinly slice them and set the greens to one side for later. Peel and grate or crush the garlic.

Stir the spring onion whites and garlic into the veg with 2 tsp cumin seeds and the harissa paste (this is SPICY, so use as much or as little as you prefer. You can add half now and stir the rest in at the end if you prefer to test the heat). Cook, stirring, for 1 min till the pan is aromatic.

Pour in 600ml boiling water. Pop a lid on the pan, bring to the boil then turn the heat down and simmer for 10 mins till the veg are very tender.

While the soup simmers, place a frying pan on a medium heat. Add 1/2 tbsp oil and the spring onion greens. Season with salt and pepper and sizzle, stirring, for 2-3 mins till just browned. Take off the heat.

Roughly chop the parsley, leaves and stalks. Add half to the pan. Blend the soup in the pan with a hand-held blender or ladle the soup into a blender and blitz till smooth. Taste the soup and add more salt, pepper or harissa if you think it needs it.

Ladle the soup into bowls and top with the spring onions and the remaining parsley to serve.