1. In a saucepan, heat the olive oil. Add the onion, carrot, garlic, and celery. Cook for 3 minutes.
2. Add the vegetable broth, 250g of drained beans, and the tomatoes. Bring to a boil. Reduce heat and cook for 50 minutes. Season with salt and pepper.
3. Remove from heat and blend the stew with an immersion blender or food processor to obtain a smooth and creamy texture.
4. Serve the stew garnished with the remaining white beans, coriander, and chopped chives.