In 3 1/2- to 4-quart slow cooker, mix carrots and onion. In small bowl, mix bouillon, cumin, cinnamon and red pepper. Sprinkle over vegetables.
Top vegetables with chicken thighs. Pour 1 1/2 cups water and the lemon juice over chicken.
Cover; cook on Low heat setting 8 to 10 hours.
Gently stir zucchini, summer squash and chick peas into stew. Cover; cook 30 minutes longer. Meanwhile, during last 5 minutes of cooking, prepare couscous as directed on package, using 2 cups water, the oil and salt. Spoon couscous into individual shallow bowls. Top each with stew.