Moroccan Vegetable Stew

2 Tablespoons olive oil
3 cloves garlic, minced
1 teaspoon dried coriander
1 teaspoon dried cumin
½ teaspoon cayenne pepper
¼ teaspoon cinnamon
5 cups vegetable broth
2½ cups diced eggplant, about 2 medium
2 cups peeled and sliced carrots, about 5 small
2 cups cauliflower florets, about one small head
2 cups sliced zucchini, about 2 medium
1 cup chopped onion, about 1 medium
29 ounces canned stewed tomatoes
15 ounces canned garbanzo beans
1 cup chopped roasted almonds
¾ cup currants
1 Tablespoon coarse salt
½ cup non-fat plain yogurt (optional)