In a large saute pan, over medium heat, melt the butter. Add the onions. Season with salt and pepper. Saute for 2 minutes. Add the carrots, peppers, and fennel. Season with salt and pepper. Saute for 2 minutes. Add the garlic and tomatoes, continue to saute for 1 minute. Add the wine and bring the liquid to a simmer. Cook for 2 minutes. Add the Pernod and cream and bring the liquid to a boil. Add the mussels. Season with salt and pepper. Cover with a lid. Cook for about 4 to 5 minutes or until all of the shells have opened. Remove from the heat and discard any shells that do not open. Serve the mussels and liquid in a deep bowl. Serve with crusty bread.