- Rinse mussels under cold water for 1 to 2 minutes. Throw out any that are open. Set aside.
- In a large saucepan, sauté onion for 1 or 2 minutes.
- Add undrained tomatoes and herbes de Provence and bring to a boil.
- Add mussels and stir to combine.
- Cover and cook for 5 to 7 minutes, or until mussels open (throw out any that stay closed).
Side suggestion: Serve mussels with homemade oven-baked fries and a green salad.