How to Make It
Heat oven to 400° F. Heat the oil in a large ovenproof skillet over medium-high heat. Add the fennel, onion, and ¼ teaspoon each salt and pepper. Cook, tossing frequently, until beginning to soften, 8 to 10 minutes. Add the wine.
Season the cod with the coriander and ¼ teaspoon each salt and pepper and nestle in the vegetables. Transfer the skillet to oven and roast until the cod is opaque throughout, 8 to 12 minutes.
Meanwhile, cook the couscous according to the package directions. Fluff with a fork and fold in the spinach. Serve with the cod and vegetables.