Add the onion, bay leaf, cloves and peppercorns to the milk. (You can, if you wish, cut the onion, insert the bay leaves and then stick in the cloves thus making it easier to remove later.) Bring to the boil and leave to infuse for 15 minutes. Strain and set aside, discarding the onion and aromatics. Melt 25g of the butter in the pan and sprinkle in the flour until you have a smooth paste – it should be of double cream consistency. Gradually pour on the milk until you have a sauce that coats the back of a spoon. Add the parsley and season to taste. Warm the cream with the spring onions and then whisk into the mashed potato with the rest of the butter until luxuriously creamy. Season with salt and pepper. Set aside and keep warm. To cook the scallops, brush lightly with oil and season with salt and pepper, and pan fry in a hot pan fir 2 minutes or so on each side until caramelised and golden. Transfer to serving plates. Finally, add a little butter to a pan, toss in the cabbage and swirl around and serve along with the champ, coating the dish with the parsley sauce.