Coat a hot skillet with melted butter. Add the fresh Prince Edward mussels to the skillet, and cover. The steam will cook the mussels, along with the heat of the pan. It will take about 1-2 minutes to cook the mussels. You'll know when they're done when the mussels begin to open. Next, add into the pan: 4 oz chopped onions, 2 oz chopped garlic, 14 oz chopped tomatoes. Add 2 ounces of sambuca (licorice flavored liquor) - let the alcohol cook off, then add fresh basil, lemon juice and lemon butter sauce to the pan. Cook for 45 seconds. Discard any mussels that did not open. Serve in a large bowl, topped with fresh chopped parsley. Lemon Butter Sauce. Melt butter over low heat;remove from heat and let sit until the milk solids settle to the bottom; skim the clear butter from the top; discard the sediment. Sauté onion and garlic in 2 tbs of the clarified butter until transparent. Stir in lemon juice and white wine and season with salt and pepper. Simmer 2-3 minutes to reduce liquid. Remove from heat and swirl in cold butter until sauce is smooth and butter is melted.