Step 1

Heat oil in a large pot or Dutch oven over medium heat. Add leek; cook, stirring often, until very tender, about 10 minutes. Add onion, carrots, celery and parsnips; cook, stirring occasionally, until the vegetables are slightly tender, 6 to 8 minutes. Stir in garlic, oregano, salt and pepper; cook, undisturbed, until fragrant, about 1 minute. Add kale; cook, stirring often, until it's just starting to wilt, about 2 minutes. Pour in broth; bring to a boil over medium heat. Cover, reduce heat to medium-low and simmer, stirring occasionally, until the kale is tender, about 20 minutes.

Step 2

Meanwhile, bring a large pot of water to a boil over high heat. Cook pasta according to package directions. Drain and set aside.

Step 3

Mash half of the beans in a medium bowl with a fork or potato masher until a chunky paste forms. Stir the mashed beans, the remaining whole beans and 1 cup water into the soup. Cook over medium-high heat, undisturbed, until warmed through, about 5 minutes. Divide the pasta among 6 bowls; ladle the soup over the pasta. Garnish with parsley and additional pepper, if desired.