Rinse the dried white beans under cold water, place them in a pot and cover with chicken broth. Bring to a boil and then simmer for about an hour until beans are tender.

While beans are simmering, heat olive oil in a skillet over medium heat. Cook chopped bacon until crispy, about 5 to 7 minutes. Set aside the bacon but keep the drippings.

In the same skillet, sauté chopped onion, carrots, and celery in the bacon drippings for 5 to 7 minutes until softened. Add minced garlic and cook for another minute.

Combine the cooked vegetables with the beans along with crispy bacon, thyme, bay leaf, salt, and pepper. Simmer for an additional 20 minutes.

If using, stir kale or spinach into the soup during the last 5 minutes of cooking. Remove bay leaf before serving.