To make the cucumber yoghurt, combine the yoghurt, garlic, lemon and cucumber and season to taste. Add the butter and olive oil to a non-stick pan and pan-fry the fish in batches over a medium to low heat, about 3-4 minutes, until golden and cooked through. Serve hot with cool cucumber yoghurt and wilted baby spinach.
Tip: you can also oven-bake the fish.
Recipe by Hannah Lewry for City Press iMagazine.