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.