In a large heavy pot with a lid, such as a Dutch oven, heat the 1 tablespoon olive oil over medium heat.
Add the diced 1 large onion and cook until softened and starting to brown, about 3 minutes.
Add the 1 lb. ground beef and cook until fully browned, breaking apart as it cooks with a wooden spoon, about 5 minutes.
Add the 6 oz. tomato paste, 1 teaspoon kosher salt, black pepper to taste, ¼ teaspoon ground cinnamon, and 1 heaping teaspoon dried spearmint.
Stir to coat the meat in the tomato paste and spices and cook until tomato paste begins to brown, about two minutes.
Add the 4 cups water; bring to a boil.
Add 1 cup orzo; stir, cover, and simmer on low, stirring occasionally, until orzo is cooked (approximately 20 minutes).
Serve with grated romano cheese, fresh chopped mint or parsley, and/or extra-virgin olive oil, for serving, if desired.
