Line a baking sheet with parchment paper, wash and dry fish fillets (I dab them dry with a napkin), salt and pepper the fillets on both sides and place on the lined sheet.
Cut the butter into thin stripes and place on top of the fillets.
Once oven is hot, add the fish and bake for 12-15 minutes (depending on thickness).
While fish is baking, bring a little over a cup of water to the boil in a kettle or pot.
If using a pot, add a vegetable stock cube and whisk, once water is boiling, stir in couscous, remove from heat, cover with lid and let stand for 10 minutes.
If using a kettle, add couscous and crumbled vegetable stock cube to a small bowl, pour water over couscous, shake once or twice to make sure couscous cooks evenly, immediately cover with a plate and let sit for 10 minutes.
In the meantime, wash and dry basil and coriander leaves and wash and deseed bell pepper.
Chop herbs and bell pepper finely.
Remove lid/plate from couscous, add 1 Tbsp olive oil and fluff with a fork then add herbs, bell pepper, juice of half a lemon and season with salt and pepper if necessary.
Fish should be ready by now, serve over a bed of herb couscous.