01 - Heat olive oil in a large pot or Dutch oven over medium-high heat. Add beef pieces and sear on all sides until browned, about 5 minutes. Remove beef from pot and set aside.
02 - In the same pot, add onion, garlic, carrots, and celery. Sauté for 5 minutes until vegetables begin to soften.
03 - Stir in red bell pepper, zucchini, and green beans. Cook for another 3 minutes to slightly soften.
04 - Return beef to the pot. Add diced tomatoes with juice, tomato paste, beef broth, water, thyme, oregano, bay leaves, salt, and pepper. Stir everything together thoroughly.
05 - Bring mixture to a boil, then reduce heat to low. Cover and simmer for 30 minutes until beef and vegetables are tender.
06 - Add orzo pasta to the simmering soup. Cook uncovered for 10 minutes, stirring occasionally, until orzo is al dente.
07 - Stir in fresh spinach and cook until wilted, about 2 minutes. Taste and adjust seasoning with salt and pepper as needed.
08 - Remove and discard bay leaves. Ladle hot soup into bowls and garnish with chopped fresh parsley.