In a small bowl, toss the fennel and shallot with lemon zest. Cut the lemon into wedges and set aside.
To serve, arrange cooked couscous, chicken, fennel, and lemon wedges on a platter and top with a few spoonfuls of the pan juices. Sprinkle herbs, including 2 tablespoons minced fennel fronds, over top, scatter the olives, and serve!