In a large pot, heat the olive oil over medium heat. Add the chopped onion, carrots, and celery. Sauté for about 5-7 minutes, or until the vegetables are softened.
Stir in the minced garlic, dried thyme, and smoked paprika. Cook for an additional 1-2 minutes until fragrant.
Add the drained butter beans and vegetable broth to the pot. Bring to a boil, then reduce the heat and let it simmer for 15-20 minutes.
Using an immersion blender, blend the soup until smooth and creamy. If you don’t have an immersion blender, carefully transfer the soup in batches to a regular blender and blend until smooth.
Stir in the lemon juice and season with salt and pepper to taste. Heat through for another 2-3 minutes.
Serve hot, garnished with fresh parsley.