Preheat the oven to 350 degrees F (180 degrees C). Scrape the scales off the fish. Slit and gut it. Combine the butter and mace and spread half on the inside cavity. Chop the leek or onion finely and mix with the herbs. Stuff into the salmon. Either sew up the fish or fasten with the skewers. Place on a baking tray, and spread with the rest of the butter and mace. Pour over a glass of white wine and sprinkle with cloves, pepper, and salt. Cover with foil and bake for 30 to 45 minutes depending on the size of the fish. Pour the fish juices over to serve.