Steamed Mussels

I'd had mussels in New York, even as a child, but never did they look so appealing as they did my first night in Rome, laced with onion, garlic, tomato, parsley, and lemon. Since then I've learned to love and prepare mussels in a variety of ways, but I always come back to these. Serve with lots of bread for sopping up the broth.
- 2 tablespoons extra virgin olive oil
- 1 medium onion, chopped
- 6 garlic cloves, peeled and lightly smashed
- 1 cup cored and chopped tomato, optional
- 4 pounds mussels, cleaned
- Fresh parsley leaves or sprigs for garnish
- 1 lemon, quartered
Instructions:
- Put the oil in a saucepan large enough to hold all the mussels and turn the heat to medium. A minute later, add the onion and garlic and cook, stirring occasionally, until the onion begins to soften, 5 minutes. Add the tomato, if using, and raise the heat a bit; cook for 5 minutes more, until the tomato begins to break up.
- Add the mussels, turn the heat to high, and cover the pot. Cook, shaking the pot occasionally, until they all (or nearly all) open, about 10 minutes. Turn off the heat.
-  Scoop the mussels into a serving bowl. Strain the accumulated liquid through a fine strainer— preferably one lined with cheesecloth—and pour it over the mussels. Garnish with parsley and serve with the lemon wedges.