Peel and finely chop the onion. Peel and grate the ginger. Place a large pan on a medium heat and add 1 tbsp oil add the onion. Fry for 5 mins to soften.

While the onion cooks, trim, peel and chop the carrots into 2cm-thick chunks. Peel the sweet potato and chop to match.

Add the ginger to the onion with 1 tbsp Bombday spice blend and a good pinch of salt. Cook, stirring, for 1 min. Add the carrots and potato and stir together.

Pour in 900ml boiling water and pop on a lid. Simmer on a low heat for 25 mins till the carrots are tender.

While the soup simmers, place a small, dry frying pan on a medium heat. Tip in the sunflower seeds with a good pinch of salt and toast for 2-3 mins till the seeds start popping. Carefully tip on to a plate. Zest the lime and squeeze the juice from half into a small bowl. Roughly chop the coriander stalks, setting the leaves to one side.

When the soup has simmered for 25 mins and the carrots are soft, add the lime zest, juice and coriander stalks. Blitz the soup with a hand-held blender till smooth, or transfer it to a blender and blend till smooth.

Taste the soup and add more salt or some pepper if you think it needs it. Serve in warm bowls topped the toasted sunflower seeds, coriander leaves and 1 tsp olive oil each. Squeeze over wedges of lime to taste.