In a medium stockpot heat the broth over medium heat and saute the onion and garlic until tender. Add the tomatoes and their juice, orange juice, orange zest, cinnamon, nutmeg, ginger and salt and pepper. Bring to a boil over high heat, reduce to medium-high and simmer partially covered for about 30 minutes. Cool slightly. Puree, using an immersion blender or food processor fitted with a metal blade. Reheat, garnish with the mint and serve immediately.