Bring the chicken stock to a boil and add couscous. Cover the pot with foil, and set aside for a couple of minutes.
Cut the bell peppers, chili, and red onion into small cubes. Then stir fry the vegetables in fry pan over high heat.
Add the juice from the lime and olive oil to the couscous, season with salt and pepper, and set aside.
To prepare the cucumber yogurt salad, cut the cucumber into half, remove the seeds, and slice. Mix the cucumber slices with the yogurt and garlic. Season with lime, salt and pepper.
Season the cobia with the Cajun spices, salt and pepper, to taste. Grill the fish on each side for about 4 minutes or until golden and the fish flakes easily. Dress with some fresh coriander leaves and olive oil.