01 - Heat olive oil in a large pot or Dutch oven over medium-high heat. Add beef stew meat 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 and become fragrant.
03 - Stir in red bell pepper, zucchini, and green beans. Cook for another 3 minutes to slightly soften the vegetables.
04 - Return the seared beef to the pot. Add diced tomatoes with their juice, tomato paste, beef broth, water, dried thyme, dried oregano, bay leaves, salt, and pepper. Stir everything together thoroughly.
05 - Bring the mixture to a boil, then reduce heat to low. Cover the pot and simmer for 30 minutes, until the beef is tender and vegetables are cooked through.
06 - Add orzo pasta to the simmering soup. Cook uncovered for 10 minutes, stirring occasionally to prevent sticking, until orzo is al dente.
07 - Stir in fresh spinach leaves and cook until wilted, about 2 minutes. Taste and adjust seasoning with additional salt and pepper if needed. Remove and discard bay leaves before serving.
08 - Ladle hot soup into serving bowls and garnish with chopped fresh parsley. Serve immediately while hot.