In a large dutch oven or stock pot, heat Olive Oil over medium heat until glistening and hot.
Add yellow onion and sauté until softened and beginning to brown, about 5-7 minutes.
Once onion is beginning to brown, add minced garlic and stir for an additional 30 second to 1 minute or until fragrant.
Add broth, parmesan rind and bay leaf to pot and bring to a boil for 1 minute. Then turn heat to medium-low and simmer partially covered for 8-10 minutes.
Once broth has simmered, add beans, celery, salt and pepper and continue to gently simmer partially covered for an additional 8-10 minutes, or until beans and celery are fork tender and heated through.
Turn heat to low and add parsley, cilantro, green onion, spinach, salsa verde, lime juice and red pepper flakes. Stir for 1-2 minutes or until spinach and herbs are completely wilted.
Remove the Parmesan Rind and Bay Leaf, and season to taste with red pepper flakes, salt and pepper. Enjoy hot with a side of whole grain bread or a side salad!