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 seared beef to the pot. Add diced tomatoes with juice, tomato paste, beef broth, water, dried thyme, dried 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 and vegetables are tender.
06 - Add orzo pasta to simmering soup and 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 salt and pepper as needed. Remove and discard bay leaves.
08 - Ladle hot soup into serving bowls. Garnish each portion with chopped fresh parsley before serving.