Trim fennel and cut into 1/4-inch thick wedges. Reserve fronds for garnish.
Heat 2 tbsp olive oil in a large skillet over medium heat. Add fennel and cook, stirring occasionally, until tender and caramelized, about 10-15 minutes. Add coriander, chickpeas, olives and lemon juice to pan and stir to combine. Continue to cook over medium heat, stirring occasionally.
Meanwhile, juice the orange into a liquid measuring cup and top off with water to make 1 1/2 cups of liquid. Add liquid to a small saucepan along with 1 tbsp olive oil, orange zest, lemon zest, and salt. Bring to a boil and stir in couscous. Cover, remove from heat and let stand for at least 5 minutes.
To serve, fluff couscous grains with a fork and spread on a dish. Spoon chickpeas and fennel over couscous and garnish with fennel fronds.