Heat the olive oil in a large pot over medium heat. Add the ground beef and cook until browned, breaking it up with a spoon as it cooks.
Stir in the onion and garlic. Cook for 3 minutes until the onion softens.
Pour in the diced tomatoes and beef broth. Add the thyme, rosemary, salt, and pepper. Bring the mixture to a simmer.
Cover and cook for 15 minutes, stirring once or twice.
Add the zucchini slices and olives. Simmer uncovered for 10 more minutes until the zucchini is tender but still holds its shape.
Taste and adjust salt or pepper if needed before serving.