Cold sweet potato soup
During a trip to Tokyo, on the morning of our departure, I tried a dish called ‘sweet potato soup’. As I took the first spoonful, I was surprised - I didn’t expect it to be cold, nor so light. It was vegan too, slightly sweet and earthy, with a velvety texture. This is my version.
I wanted the purity of the sweet potato to shine, so I have used very few ingredients here. Just onion for fragrance, vegetable stock for savoriness and soy milk for body. Other non-dairy milks would work too – I’m fairly sure the one I tried in Tokyo was made with coconut milk so that would be a nice option too, and oat milk would give a rich result too.
Satsumaimo are sweet and starchy, with a reddish-purple skin and pale yellow or white interior. If you can’t find this variety, use regular sweet potato. It will look different, more orange in hue, but the flavor will be just as good.
Cold Sweet Potato Soup
Ingredients
- extra virgin olive oil
- 1 brown/yellow onion thinly sliced
- 450 g Japanese sweet potato about 1 medium, peeled and diced
- 500 ml vegetable stock
- 500 ml soy milk or more to serve
- chopped chives to serve
Instructions
- Heat a large pot or Dutch oven on medium high. Drizzle with olive oil and add the onions, and stir until slightly softened, about 2 minutes (we don’t want them to brown, so reduce heat if it starts to turn golden). Next, add the sweet potato and season with salt and toss for 2 minutes. Pour in the vegetable stock, cover, reduce heat to low and cook until the sweet potato are falling apart, 15-17 minutes. Allow to cool for 10 minutes.
- Transfer the sweet potato mixture to a blender (or use a handheld immersion blender) and add the soy milk. Puree until completely smooth. Taste and season well with salt and black pepper.
- Transfer to a bowl and cover (or use an airtight container) and place in the fridge to chill until ready to eat.
- When ready to eat, if the soup has thickened up, loosen it up by adding 1/2 cup soy milk or water. Ladle into bowls and season each with black pepper, a few drops of olive oil and chives.
