Silly name, but what a great dish! Omega 3 refers to all the lovely goodness that you get from oily fish like red mullet, sardines and fresh anchovies, so do feel free to use any one of these, or a mixture of them. This is also great served with linguine pasta instead of couscous.
First of all, lay your fish out in one layer on your worktop to give you an idea of how much you are dealing with. Next get yourself a pan with a lid – ideally one that’s the right size for the fish to be spread out in one layer. This is so that it can all cook at the same time. Put your pan on the heat, add 4 or 5 tablespoons of olive oil, and slowly fry your onions, fennel, chilli, fennel seeds and bay leaf with the lid on until nice and softened. This should take about 10 minutes.
Meanwhile put your couscous in a bowl and just cover it with salted, boiling water. Put to one side to soak for about 5 minutes. When the onions are sweet and soft, add the tomatoes and anchovies, stir together and carefully season to taste. Shake the pan so that the onions and tomatoes cover the bottom of the pan evenly. Dress the couscous lightly with a little olive oil and the juice and zest of one of the lemons. Sprinkle the couscous over the top of the onions and tomatoes in one even layer. Then place the fish over the top of that and finish off with a drizzle of olive oil. Place the lid on top and simmer slowly on the hob for about 12 minutes.
Meanwhile, season the yoghurt with salt, pepper and the remaining lemon juice and sprinkle over the reserved fennel tops and mint. Serve the pan of fish in the middle of the table with a bowl of yoghurt and let everyone help themselves. Lightly stir the fish up, check the seasoning and eat straight away.