In a large heavy-bottomed pot over medium heat, add olive oil and butter.

Add sliced onions and a pinch of salt. Cook, stirring occasionally, until the onions turn golden and deeply brown at the edges — about 25–30 minutes.

If onions are browning too fast, lower the heat and add a splash of water to deglaze.

When onions are nicely caramelized, add the minced garlic, thyme, and smoked paprika (if using), and cook for 30–60 seconds until fragrant.

Add the drained white beans and chicken broth to the pot.

Use a wooden spoon to scrape any brown bits from the bottom. Bring to a gentle simmer.

For a silky texture, use an immersion blender to puree about half the soup right in the pot, or ladle 2 cups into a blender, pulse until smooth, then return it.

Stir in shredded chicken and bay leaf. Simmer for 8–10 minutes to heat through and let flavors meld.

Remove bay leaf, stir in lemon juice, and season with salt and pepper to taste.

Ladle into bowls, garnish with parsley and Parmesan if you like, and serve with crusty bread for dunking.

Leftovers taste even better the next day.