Preheat the oven to 240C/460F (220C fan). Place the tomatoes to one side of an oven tray and the chopped red onion and yellow pepper to the other side of the tray.
Drizzle all over with olive oil and season with salt and pepper.
Pop in the oven for 10 minutes.
Meanwhile, put the couscous in a large heatproof bowl with the stock cube.
Cover with 200ml of boiling water, stir well, cover and leave to stand for 5 minutes.
Tip the cans of Princes Mackerel Fillets in a Moroccan Style Sauce with Apricot Purée onto a microwaveable plate and break into large pieces with a fork. Microwave for 30 seconds on High.
Once everything is ready, fluff up the couscous, tip all of the quick roasted veg except the tomatoes into the bowl.
Serve the couscous onto four plates.
Top with the Princes Mackerel Fillets in a Moroccan Style Sauce with Apricot Purée.