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