Heat 2 teaspoons vegetable oil in a Dutch oven over medium-high heat; add half of beef, browning on all sides. Remove from pan. Repeat the procedure with remaining oil and beef. Add onions, ginger, aniseed, and garlic to pan; sauté 30 seconds. Stir in broth, scraping pan to loosen browned bits. Return beef to pan. Add 2 3/4 cups water and next 5 ingredients (2 3/4 cups water through cinnamon sticks), and bring to a boil. Cover, reduce heat, and simmer 1 hour.
Add the turnips and carrots; simmer for 45 minutes or until tender. Combine 1 tablespoon water and cornstarch; add to beef mixture. Bring to a boil; cook for 1 minute, stirring frequently. Add spinach; cover and cook for 3 minutes or until wilted. Discard the cinnamon sticks.