Heat the oil in a large saucepan on medium heat. Add the onion, carrot, and celery and soften for 6-8 minutes, stirring now and then. Season with salt and pepper.
Once the veg has started to soften, stir in the garlic and potatoes and cook for another 2-3 minutes.
Add the cumin, coriander, smoked paprika, sage, and tomato puree. Stir everything well and cook for another minute.
Add the drained black beans, vegan stock, bay leaves, and nutritional yeast. Mix well, bring to a gentle simmer, then reduce the heat and cook on a low heat for around 15 minutes or until the potatoes have softened.
Once the potatoes are soft, turn off the heat and remove the bay leaves.
Blitz using a hand blender or transfer to a larger blender, working in batches if necessary. For a chunkier texture, simply mash the soup with a potato masher. Adjust the seasoning and serve.
Notes
Store any leftovers in an airtight container in the fridge for up to 4 days, or freeze for up to 3 months.