Heat a large pot or Dutch oven over medium heat. Add chopped bacon and cook until lightly browned and some fat has rendered.
Add the chopped onion and cook for about 3 minutes, until softened.
Stir in the minced garlic and cook for about 30 seconds.
Add diced tomatoes with their juice. Stir and simmer for about 5 minutes.
Add the drained green beans and gently stir them into the tomato and bacon mixture.
Pour in the beef broth. Add black pepper and a small amount of salt.
Bring to a gentle simmer, then reduce the heat to medium-low and cover.
Cook for 20–25 minutes, stirring once or twice, until the beans are tender and flavorful.
Taste and adjust the salt or pepper if needed. Let the beans rest for about 5 minutes before serving.