01 -
Cook the bacon in a large saucepan or pot until crisp. Set aside on paper towels to drain, and drain all but 2 tablespoons of the grease from the pan.
02 -
Add the onions, celery, and carrots to the saucepan and cook over medium-high heat until tender, about 7-10 minutes.
03 -
Add the garlic and red pepper flakes (if using) and cook until fragrant, about 1 minute.
04 -
Add half a cup of the broth and deglaze the pan by scraping up the brown bits off the bottom with a wooden spoon as the broth simmers.
05 -
Add the remaining broth along with the beans, thyme, and bay leaves. Bring to a boil, reduce the heat, and simmer covered for 1.5-2 hours until the beans are tender. Remove the bay leaves.
06 -
Turn off the heat, add the parmesan, and let it melt into the soup.
07 -
Add the cooked bacon back into the soup. Season with salt and pepper to taste before garnishing with parsley, if desired.