For the courgette pancakes, beat the flour, eggs and half of the milk in a bowl to a fairly loose batter, adding more milk little by little as necessary.
Stir in the grated courgette and season with salt and freshly ground black pepper.
Heat the butter and olive oil in a frying pan over a high heat. Ladle some of the courgette batter into the frying pan and swirl the pan until the mixture is evenly distributed. Fry for 3-4 minutes on each side, or until golden-brown on both sides. Set aside on a warm covered plate. Repeat with the rest of the mixture.
To serve, pile the pancakes onto a plate. Put the Greek-style yoghurt into a small serving bowl, sprinkle it with the paprika, and serve on one side.