Sweet Potato, Coconut and Chilli Soup (+ caramelised onions)

To make this deliciously satisfying sweet potato, coconut and chilli soup, we start by giving our onions some extra loving, taking a departure from the usual method of handling onions for soups.

Rather than simply sautéing, we take the time to caramelise them for a full 20 minutes, coaxing out their natural sweetness and intensifying their flavour. This extra step infuses the soup with added depth and harmonises seamlessly with the inherent sweetness of the sweet potatoes.

Next, we introduce a generous grating of lime zest and a splash of lime juice. It's the crowning touch, infusing the soup with a burst of VA-VA-VOOM which is so often absent in many soup recipes.

Altogether, this sweet potato and coconut soup is a marvel! It's remarkably simple to prepare and perfect for making a large batch to enjoy throughout the week. Pair it with a fresh, crunchy roll and you have a wholly satisfying meal that's both easy to make and utterly delicious.

Key ingredient notes and substitutions

**Please see the recipe card at the bottom of this post for the full list of ingredients.

Sweet potatoes

For this recipe, opt for the sweet potatoes with yellow/orange flesh. The orange varieties are exceptionally sweet, contain a higher moisture content and have an appetising colour, perfect for a delicious-looking soup.

Onions

Technically, you can use any onions of your choosing. However, yellow onions are typically considered best for caramelising due to their high sugar content. They caramelise beautifully, developing rich, sweet flavours during the cooking process.

Red chilli

For those who prefer milder heat-levels, our soup recipe includes just half a red chilli for a gentle simmer, perfect for a subtle kick without overwhelming heat.

But for spice enthusiasts, feel free to add as much chilli as you wish to suit your taste buds!

The half red chilli can be replaced with a half teaspoon of red chilli flakes.

Coconut milk

Unless you're on a "no-fun" diet or have a full-cream coconut milk vendetta, go for the full-fat version! Your soup deserves that velvety, rich hug.

Lime

If there's one ingredient you absolutely can't skip or swap out in this soup, it's the lime! Need proof? Try the soup before and after adding the lime zest and juice. Big difference, yes?

Peanuts (optional)

We don't usually play favourites with "optional" ingredients, but we've got to make a special case here.

A sprinkle of chopped peanuts takes this soup to a whole new level. It's the perfect match for the sweet potato, coconut, ginger and chilli flavours. Give it a go if you can – you won't regret it!

Step-by-step instructions

1. In a large saucepan, heat the oil (olive oil, veg oil, coconut oil etc) over medium heat. Add the sliced onions, cover with a lid and cook undisturbed for 5 minutes.

2. After 5 minutes, remove the lid and reduce the heat to low. Cook the onions gently for an additional 15 minutes, stirring frequently. If it seems like the onions are sticking, add a tiny splash of water.
   
   The onions should now have developed a rich, golden-brown colour. Exercise caution to prevent the onions from burning, as it can impart a bitter taste.

3. Add a small splash of water and briefly deglaze the pan by scraping the bottom with a spoon to release any stuck-on bits. This will add flavour to the soup.

4. Next, add the chopped red chilli, chopped garlic, ginger paste (or fresh ginger) and turmeric. Increase the heat to medium and stir the spices into the caramelised onions for 1-2 minutes or until they smell fragrant.

5. Add the chunks of sweet potato and stir them into the onion mixture for 2-3 minutes.

6. Add the prepared vegetable stock, coconut milk, salt and black pepper. Stir everything together and bring it up to a simmer. Cook over medium-low heat for 20-25 minutes or until the sweet potatoes are soft and break apart when pierced with a fork.

7. Use a stick blender (immersion blender) to blend the soup into a smooth, thick consistency with no visible chunks. Alternatively, transfer the mixture to a food processor and blend until smooth.
   
   If you prefer a thinner soup, add more coconut milk, cream, vegetable stock or water.

8. Finally, add the zest of one whole lime and the juice of half a lime. Test for seasoning and add more salt if needed. If you prefer an extra zing, feel free to add more lime juice.

9. Spoon the soup into bowls and garnish with your favourite toppings, such as sliced chilli, fresh coriander leaves, chopped peanuts, extra black pepper or a swirl of coconut milk or cream.

Variations

• Include additional vegetables like bell peppers, carrots, or spinach.
• Consider adding lentils or chickpeas for added vegetarian protein.
• Add cooked chicken, shrimp or tofu for a protein boost.
• Experiment with different herbs like lemongrass or Thai basil.
• Add curry powder or a spoonful of green curry pasta or red curry paste for an extra kick.
• Try drizzling some sesame oil for a nutty aroma.
• Toasted coconut flakes can be used as a crunchy topping.
• Add a pinch of cinnamon or cumin.
• Stir in a dollop of Greek yoghurt or sour cream just before serving for a creamy finish.
• Add a sachet of coconut cream for extra creaminess and coconut flavour.
• Add lime leaves along with the sweet potato chunks. Remove before blending.

Serving Suggestions

• Serve with crusty rolls, chilli cheese toast or a sourdough cheese toastie.
• Spoon the soup over a bed of cooked rice or quinoa for a more substantial meal.
• Garnish with a variety of toppings such as sliced chilli, fresh cilantro/coriander, chopped peanuts or a swirl of coconut milk.
• Provide lime wedges on the side for those who want an extra squeeze of lime.
• Add creamy avocado slices as a topping to complement the soup's richness.
• Sprinkle crispy shallots or fried onions on top.
• Drizzle herb-infused oil, such as basil or rosemary oil, over the soup.
• Grate a bit of Parmesan, feta or goat cheese over the soup for a savoury touch.
• Add a side of pickled vegetables like cucumbers or radishes for a tangy contrast or add a simple salad.

Storage, reheating and freezing

Storage

Once your sweet potato, coconut and chilli soup have cooled to room temperature, transfer it to an airtight container. Refrigerate promptly to maintain freshness. Properly stored, the soup can last in the fridge for up to 3-4 days.

Reheating

To reheat the soup, place it in a saucepan over medium heat. Stir occasionally to ensure even heating. If the soup has thickened, you can add a splash of water or vegetable broth to reach your desired consistency.

Alternatively, use a microwave-safe bowl and heat in short intervals, stirring between each, until warmed through.

Freezing

For longer storage, freezing is an excellent option. Allow the soup to cool completely before transferring it to a freezer-safe container, leaving some room for expansion. Freeze for up to 2-3 months.

To thaw, place the container in the fridge overnight. Reheat using the methods mentioned above, adjusting consistency as needed. While the texture may vary slightly after freezing, the flavours should remain intact.

More side dishes for soup

Best sourdough grilled cheese

Chilli cheese toast

Cypriot grain salad

Pizza toast

Easy 2-ingredient flat breads

Masala chips

Danish bread rolls

Easy cheesy green pea fritters