Make the Dijonnaise Garnish: Bring a large pot of salted water to a boil. Add the carrots and cook for 5 minutes. Add the spinach and cook for 1 minute more; drain well and squeeze the excess water from the spinach. Melt the butter in a large skillet over medium heat. Add the carrots and spinach and season with salt and pepper. Cook until well coated with the butter. Spoon onto a serving platter and keep warm.
Make the Seared Cod: Heat the olive oil in a nonstick skillet over medium-high heat. Season the fillets with salt and pepper and slip them into the pan, skin side down, along with the garlic and thyme. Sear the fillets for 3 minutes, turn them over and cook for 3 minutes more. Reduce the heat to medium, add the butter and cook another 3 minutes, or until the fish is opaque, moist and lightly firm when pressed.
Preheat the broiler.
Place the seared cod in a foil lined broiler pan. Spread the mustard evenly over the fillets. Mix together the bread crumbs, chives, and olive oil and pat evenly over the fish. Broil just until the crumbs are golden brown.
Spoon the Dijonnaise Garnish onto a serving platter, top with the cod, and sprinkle with parsley.