1. Preheat the oven to 200 degrees and prepare the broth.
2. Cut the carrots in half lengthwise, then slice them into half-moons.
3. Arrange the carrots in the baking dish and drizzle with half of the olive oil.
Make sure they are well coated with a layer of oil, then season with salt and pepper.
4. Bake for 10 minutes.
5. Add the cherry tomatoes to the carrots, stir, and bake for an additional 15 minutes.
6. Meanwhile, finely chop the parsley and separate the watercress leaves.
7. Heat the remaining olive oil in the covered saucepan.
8. Add the pearl couscous and sauté for 1 minute over medium-high heat.
9. Pour in the broth and raisins, then cover and cook over low heat for 12 minutes.
10. Fluff the couscous with a fork and set aside uncovered.
11. Stir in ⅓ of the parsley, then season with salt and pepper.
12. Meanwhile, melt half of the butter in the skillet over medium-high heat and cook the cod fillet for 1 to 2 minutes on each side.
13. Season with salt and pepper.
14. Keep warm in aluminum foil.
15. Reserve the skillet with the cooking juices.
16. Heat the remaining butter in the skillet with the cooking juices and add ⅓ of the parsley.
17. Season with salt and pepper, then stir well.
18. Mix the cherry tomatoes and carrots with the pearl couscous.
19. Serve on plates and garnish with watercress and the remaining parsley.
20. Serve with the cod fillet and butter sauce.