Moroccan Sweet Potato Stew

2 teaspoon(s)  olive oil
1 medium yellow onion, chopped
3 clove(s) garlic, crushed with press
1 1/2 teaspoon(s) curry powder
1 1/2 teaspoon(s) ground cumin
1/4 teaspoon(s) ground allspice
1 can(s) (14.5 ounces) diced tomatoes
1 can(s) (14 to 14.5 ounces/1.75 cups ) reduced-sodium chicken broth
1 cup(s) no-salt-added garbanzo beans (chick peas), rinsed and drained
1 large (about 16 ounces) sweet potato, peeled and cut into 3/4-inch chunks
2 small (about 6 ounces each) zucchini, cut into 3/4-inch chunks
1 cup(s) whole-grain couscous
1/4 cup(s) loosely packed fresh mint leaves, chopped

1. In nonstick 12-inch skillet, heat oil over medium heat. Add onion and cook 8 to 10 minutes or until tender and lightly browned, stirring occasionally. Stir in garlic, curry powder, cumin, and allspice; cook 30 seconds.
2. Add tomatoes, broth, beans, and sweet potato; cover and heat to boiling over medium-high heat. Reduce heat to medium; cover and cook 10 minutes. Stir in zucchini and cook, covered, 10 minutes or until vegetables are tender.
3. Meanwhile, prepare couscous as label directs.
4. Stir mint into stew. Serve stew with couscous.