Microwave broth over high heat in a 1-quart glass measuring cup until piping hot, 3 to 4 minutes.
Heat oil in a large saucepan over medium-high heat. Add onion and garlic; saute until softened, 2 to 3 minutes. Add carrots, couscous and chickpeas; stir to combine. Stir in stock, cover and turn off heat. Let stand until stock is completely absorbed, 4 to 5 minutes. Add salt, if necessary, and pepper to taste. Fluff with a fork, strew with the optional chopped parsley and serve with the Mixed Grill.