Peel and finely chop the onion. Peel and crush the garlic. Warm a large pan on a medium heat for 2 mins, then drizzle in 1 tbsp olive oil. Add the onion, season with a pinch of salt and pepper and cook, stirring often, for 5 mins till softened.

While the onion cooks, peel the sweet potatoes and chop them into 2cm-thick cubes. Fill the kettle and boil it.

Add the garlic, 2 tsp ground cumin and 1 tsp smoked paprika to the softened onion. Stir for 1 min then add the sweet potato with a good pinch of salt and pepper. Crumble in the stock cube and drop in half the thyme sprigs. Pour in 700ml boiling water from the kettle. Pop a lid on the pan and simmer for 20 mins till the spuds are tender.

Meanwhile, warm a small frying pan on the heat for 1 min then add 2 tsp fennel seeds. Toast for 1-2 mins till the pan smells fragrant and the seeds start to pop. Tip them out onto a plate.

Fish the thyme sprigs out of the soup and discard them. Using a hand blender, blitz the soup in the pan till it’s really smooth, or transfer it to a blender and blitz. Taste and add more salt, pepper or smoked paprika if you think it needs it.

Ladle the soup into warm bowls. Drizzle a little thyme oil over each bowl, and top with toasted fennel seeds and a few thyme leaves to serve.