Place the butter in a large pot over low heat.
When it begins to foam add the garlic, shallot, parsley, peppercorns.
Sweat for 2-3 minutes until aromatic and the garlic and shallots have sweetened and glazed.
Add the wine and tomatoes and simmer for @ 10 minutes to reduce by about 50%.
Raise heat to high and add the mussels.
Place a lid on the pot and cook for several minutes.
Every minute or so, laying a towel across the top of the pot, grip the sides of the pot, press your thumbs on top of the lid and toss the mussels in the pot to rotate the mussels form the bottom of the pan to the top.
Keep doing this until mussels have all opened.
Season to taste with the lemon juice.
Divide the mussels into bowls and spoon broth over the mussels.
Serve with the crusty bread.