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