Ingredients

• 1 medium onion, coarsely chopped
• 1 small fennel bulb, cored, coarsely chopped
• 1 carrot, coarsely chopped
• 1 celery stalk, coarsely chopped
• 2 tablespoons olive oil, plus more for serving
• 3 ounces pancetta, cut into 1/4" pieces
• 1 cup spelt
• 2 garlic cloves, chopped
• Kosher salt, freshly ground pepper
• 1 tablespoon tomato paste
• 3/4 teaspoon crushed red pepper flakes
• 12 cups low-sodium chicken broth
• 1/2 head escarole, leaves torn into bite-size pieces
• 1 15-ounce can cannellini beans, rinsed
• Shaved Parmesan (for serving)

Instructions

1. Pulse onion in a food processor until finely chopped. Transfer to a medium bowl. Repeat with fennel, carrot, and celery, placing vegetables in bowl with onion.
2. Heat 2 tablespoons oil in a large pot. Add pancetta and cook, stirring often, until golden brown, about 3 minutes. Add spelt and cook, stirring often, until grains are a couple of shades darker, about 3 minutes.
3. Add onion, fennel, carrot, celery, and garlic to pot; season with salt and pepper. Cook, stirring occasionally, until vegetables are softened, 6–8 minutes. Add tomato paste and red pepper flakes, and cook until paste is slightly darkened, about 1 minute.
4. Add broth to pot, bring to a boil, reduce heat, and simmer, partially covered, until spelt is tender, 60–70 minutes. Stir escarole and beans into soup and cook until escarole is wilted and beans are warmed though, about 4 minutes.
5. Serve soup drizzled with oil and topped with Parmesan.
6. DO AHEAD: Soup can be made 2 days ahead. Cover and chill.