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 diced onion, minced garlic, sliced carrots, and celery. Sauté for 5 minutes until vegetables begin to soften and onions become translucent.
03 - Stir in diced red bell pepper, zucchini, and trimmed green beans. Continue cooking for an additional 3 minutes, allowing vegetables to begin releasing their flavors.
04 - Return seared beef to the pot. Add diced tomatoes with 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 rolling boil, then reduce heat to low. Cover with lid and simmer for 30 minutes until beef becomes 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 pasta reaches al dente texture.
07 - Stir in fresh spinach leaves and cook for 2 minutes until wilted. Taste and adjust seasoning with additional salt and pepper as needed.
08 - Remove and discard bay leaves. Ladle hot soup into serving bowls and garnish generously with chopped fresh parsley.