Scrub and clean the mussels, removing the beards by pulling them off. Drain and set aside.
Heat a skillet over medium heat and add the olive oil. Sauté the garlic for a few moments before adding the mussels. Stir and toss the mussels, then add the white wine and diced tomatoes. Cover the skillet with the lid and steam for 1 minute, or until all the mussels are open.
Add the lemon juice, salt (to taste), and parsley. Stir to combine well and serve hot.
Notes
I served the mussels with plain spaghetti. Just ladle the sauce and the mussels over for a complete meal.