Heat olive oil in a large pot over medium heat.
Add the ground beef and cook, breaking it apart with a spoon, until browned and cooked through, about 6-8 minutes.
Remove the cooked ground beef from the pot and set aside. Drain excess fat if necessary, leaving about 1 tablespoon in the pot.
Add the diced onion, carrots, celery, and red bell pepper to the pot. Cook, stirring occasionally, until the vegetables are softened, about 5-7 minutes.
Add the minced garlic and cook for 1 minute until fragrant.
Return the cooked ground beef to the pot and stir to combine.
Add the diced zucchini, canned diced tomatoes with their juice, and beef broth to the pot. Stir in dried thyme, dried oregano, black pepper, and salt.
Bring the soup to a boil, then reduce heat to low and simmer uncovered for 25 minutes.
Add the frozen green beans and corn kernels to the soup and continue simmering for an additional 10 minutes until all vegetables are tender.
Stir in the chopped fresh parsley just before serving.
Taste and adjust seasoning with additional salt and pepper if needed.
Serve hot.