Start by gathering all the ingredients needed for the recipe.
In a saucepan over medium heat, cook the bacon, stirring frequently, until it is nearly crisp, which should take about 6 minutes.
Add the sliced onion to the pan and continue cooking until it becomes soft and golden brown, allowing the browned bits from the bottom of the pan to dissolve into the onion's juices, approximately 5 minutes.
Stir in the minced garlic and tomato sauce, cooking for an additional minute until the garlic softens.
Introduce the trimmed green beans into the skillet and pour in the chicken broth.
Increase the heat to high, then season the beans with salt, black pepper, and cayenne pepper, bringing the mixture to a simmer.
As the beans begin to soften, reduce the heat to medium-low and let them simmer for 1 ½ hours, stirring occasionally.
If the mixture appears dry, add more broth or water as needed.
Taste and adjust the seasoning with additional salt, black pepper, and cayenne pepper if desired.
Continue cooking until the beans are soft and tender, which should take about another 30 minutes.
Once done, transfer the beans along with some of the pan juices to a deep serving platter and enjoy!