Bring the broth to a boil in a saucepan, add the couscous, cover the pan and remove it from the heat.
Meanwhile, bring a large pot of water to a boil. Cut the stems and top half inch off the bell peppers and scoop out the seeds and membranes. Boil trimmed peppers for 5 minutes, then drain them upside down.
Heat oil in a nonstick skillet. Add onion, zucchini, yellow squash, fennel seeds, oregano, and salt. Cook, stirring frequently, for 5 minutes or until vegetables are softened.
Remove from heat and stir in the tomatoes and chickpeas. Using a fork, scrape the couscous into the skillet and toss with the vegetables. Stir in the crumbled feta.
Place peppers upright in the baking dish and fill them with couscous. Bake 15 minutes.