Add the bacon to a large Dutch oven and cook over medium heat until light golden (not crisp). Drain off the excess fat.
Add the onions to the pot; cook until the bacon and onions are golden brown. Add the green beans and tomatoes, and season to taste with salt, black pepper and cayenne. Stir gently to combine.
Cover the pot, reduce the heat to low and simmer for 1 hour.
2012 Ree Drummond, All Rights Reserved