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, approximately 5 minutes. Remove beef from pot and set aside.
02 - In the same pot, add diced onion, minced garlic, sliced carrots, and sliced celery. Sauté for 5 minutes until vegetables begin to soften and become fragrant.
03 - Stir in diced red bell pepper, diced zucchini, and trimmed green beans. Cook for an additional 3 minutes to begin softening the vegetables.
04 - Return browned beef to the pot. Add diced tomatoes with their juice, tomato paste, beef broth, water, dried thyme, dried oregano, bay leaves, salt, and black pepper. Stir thoroughly to combine all ingredients and dissolve tomato paste.
05 - Bring the mixture to a boil, then reduce heat to low. Cover pot and simmer for 30 minutes, or until beef is tender and vegetables are cooked through.
06 - Add orzo pasta to the simmering soup. Continue cooking uncovered for 10 minutes, stirring occasionally to prevent sticking, until orzo is al dente.
07 - Stir fresh spinach leaves into the hot soup and cook for about 2 minutes until just wilted. Taste and adjust seasoning with additional salt and pepper if needed. Remove and discard bay leaves before serving.
08 - Ladle hot soup into individual bowls. Garnish each serving with chopped fresh parsley. Serve immediately while hot.