Snap the ends off the green beans and then snap the beans in half. (discard the ends) Set aside.
In a large deep skillet or pot, melt butter over medium heat.
Saute onions until tender.
Add garlic and saute until fragrant and golden.
Add chicken broth, red pepper flakes, and turkey leg.
Simmer covered for about 15-20 minutes.
Remove turkey leg, let cool and dice into small pieces. (set aside)
Add the green beans into the pot.
Return the bone and skin to the pot.
Cover and simmer for 2 hours (or longer) or until green beans are tender. (slow and low is the BEST way to cook them)
When green beans are done, taste the broth and add salt and black pepper if needed.
Stir in the chopped turkey leg.