In a large pot, brown the ground beef over medium heat until no longer pink.
Drain excess fat and add chopped onion, cooking until translucent.
Stir in the minced garlic and cook for 1 minute.
Add diced carrots and celery, cooking for about 5 minutes.
Pour in the diced tomatoes and beef broth.
Season with oregano, salt, and pepper.
Bring the soup to a boil, then reduce heat to simmer.
Add frozen peas and simmer for an additional 10 minutes.
Taste and adjust seasonings if necessary.
Serve hot, garnished with fresh parsley.