Heat olive oil in a large Dutch oven over medium-high heat. Season beef with salt and pepper, then sear in batches until browned on all sides. Remove and set aside.

In the same pot, sauté onion until softened, about 3-4 minutes. Add garlic and cook for another minute until fragrant.

Stir in tomato paste and cook for 1-2 minutes. Add crushed tomatoes, beef broth, cinnamon stick, bay leaves, allspice, and sugar if using. Mix well.

Return seared beef to the pot and bring to a gentle simmer. Cover and cook on low heat for 1.5 to 2 hours, until beef is tender and sauce is rich.

Preheat oven to 375°F. Add orzo to the pot, mixing into the sauce. Add hot water or broth as needed to ensure orzo cooks evenly.

Transfer pot to oven and bake for 20-25 minutes, stirring occasionally, until orzo is tender.

Remove cinnamon stick and bay leaves. Sprinkle with grated Kefalotyri cheese and garnish with fresh parsley. Serve hot.