Directions

1. Heat 2 tablespoons oil in a large pot over medium-high heat. Add chopped onion and chopped celery; cook, stirring often, until the onion is translucent, about 5 minutes. Add 1 tablespoon garlic, 1 tablespoon Italian seasoning and ¼ teaspoon crushed red pepper; cook, stirring occasionally, until aromatic, about 2 minutes. Stir in 30 ounces rinsed beans, 2-ounce Parmesan rind (if using), 4 cups broth, ¾ teaspoon salt, ½ teaspoon pepper and 1 bay leaf; bring to a boil over high heat. Reduce heat to medium-low and cook, stirring occasionally, until the vegetables are tender, about 20 minutes. Remove and discard the Parmesan rind (if using) and bay leaf.
2. Pour 2 cups of the soup into a blender. Secure the lid on the blender and remove the center piece to allow steam to escape. Place a clean towel over the opening. Process until smooth, about 1 minute. (Use caution when blending hot liquids. Alternatively, pour 2 cups of the soup into a medium bowl; process until smooth using an immersion blender.)
3. Pour the pureed soup back into the remaining soup in the pot; stir to combine. Stir in ½ teaspoon lemon zest and 2 teaspoons lemon juice. Divide the soup among 4 bowls; sprinkle with ¼ cup Parmesan. Garnish with 1 tablespoon parsley, if desired.