Preheat a grill to medium high. Mix the butter, harissa, ginger, garlic, lemon juice and a pinch of salt in a small bowl.
Tear off 4 large sheets of heavy-duty foil. Divide the carrots, chickpeas and cilantro among the sheets; season with salt and pepper. Place the fish fillets skin-side up on top of the carrots. Season the fish with salt, then spread with the harissa butter. Bring two opposite ends of the foil together and fold twice to seal. Fold in one of the other sides, leaving one side open. Carefully pour 1/4 cup orange juice into each packet. Fold and seal the last side, leaving room for heat to circulate.
Grill the foil packets until the fish is opaque and cooked through, about 15 minutes. Carefully open the packets and sprinkle with more cilantro.