Dry roasted nuts and seeds (e.g. almonds, cashews, pumpkin seeds)
Handful fresh herbs (e.g. thyme and sage), roughly chopped
Heat a large pot over medium heat. Add 1/4 cup vegetable broth and onion, and sauté until the onion softens and becomes translucent, about 5 minutes.
Add garlic, celery, carrots and a pinch of salt, stir well. Cook until vegetables start to soften and brown, about 5 minutes. If needed, add a splash of broth to help prevent the vegetables from sticking to the bottom of the pot.
Next add purple sweet potato, apple, fresh herbs and vegetable broth, stir well. Raise heat and bring soup to a boil. Once the soup has reached boiling point, reduce heat to a simmer and cook until vegetables are soft, around 20-30 minutes. Set soup aside to cool for at least 10 minutes.
Optional step: While soup is cooling, dry roast nuts and seeds. Heat a skillet over medium, add nuts and seeds, and dry roast them for a few minutes until they are lightly golden on both sides. Keep a close on them as they can get roasted very quickly. Transfer dry roasted nut and seeds to a bowl and set aside.
Once the soup has cooled slightly, using an immersion blender or counter top blender, carefully blend until the soup is smooth and creamy. If you used a counter top blender, return soup to pot. Taste the soup and adjust seasoning as needed. If necessary, reheat the soup.
Ladle soup into bowls and, if using, top with dry roasted nuts and seeds, and fresh herbs.