Rinse the dried Great Northern beans under cold water and soak overnight.

Cook the thick-cut bacon in a large pot over medium heat until crispy, about 5–7 minutes. Remove and crumble bacon, keeping drippings in the pot.

Sauté the chopped onion, carrots, and celery in the bacon drippings for about 5 minutes until softened. Stir in the minced garlic and sauté for an additional minute.

Return the crumbled bacon to the pot. Add soaked beans, chicken broth, thyme, salt, and pepper. Stir to combine and bring to a boil.

Reduce heat to low, cover, and simmer gently for about 1 hour, stirring occasionally until beans are tender.

Check for tenderness and serve warm in bowls, garnished with fresh parsley if desired.