Kale is matched up here with white beans and chunks of lean pork tenderloin to create a soup that's satisfying and quick to make. Smoked paprika gives the soup a Spanish flair so some warm bread and sliced Manchego cheese would go well on the side.
Heat oil in a Dutch oven over medium-high heat. Add pork, sprinkle with salt and cook, stirring once or twice, until no longer pink on the outside, about 2 minutes. Transfer to a plate with tongs, leaving juices in the pot.
Add onion to the pot and cook, stirring often, until just beginning to brown, 2 to 3 minutes. Add garlic, paprika and crushed red pepper (if using) and cook, stirring constantly, until fragrant, about 30 seconds. Add wine and tomatoes, increase heat to high and stir to scrape up any browned bits. Add broth and bring to a boil.
Add kale and stir just until it wilts. Reduce heat to maintain a lively simmer and cook, stirring occasionally, until the kale is just tender, about 4 minutes. Stir in beans, the reserved pork and any accumulated juices; simmer until the beans and pork are heated through, about 2 minutes.