Clean mussels by putting them in water and scrubbing the outsides.
In a large skillet, over medium heat, melt butter; add shallot and sauté until aromatic, about ~3 minutes; stir in garlic and crushed red pepper; cook an additional 3 minutes.
Pour white wine into the skillet and bring to a boil; add mussels and cover; reduce heat to low; simmer ~6 minutes, or until the mussels have opened.
Pour in lemon juice and stir; let simmer for another minute or two; discard any mussels that haven’t opened.
Serve with cooking liquid and crusty bread; provide a bowl for discarding shells.
