Tarragon is one of the classical fine herbs of French cuisine together with parsley, chives, chervil and marjoram. Russian tarragon is more vigorous but has little flavour compared to the French variety.
- Scrub the mussels well in cold water and snip off any beards. Set aside.
- Heat the oil in large saucepan over medium heat. Sauté the onion, stirring until softened. Stir in the garlic and herbs and cook for 30 seconds. Add the tomatoes and tomato paste; bring to boil over high heat and boil until reduced by half, about 10 minutes.
- Add the mussels and stir well. Cover and steam over medium heat, stirring occasionally, until the mussels open, about 5 minutes. Discard any that do not open. Serve in deep bowls.
- Great served sprinkled with chopped fresh herbs and accompanied by chunks of crusty bread to mop up the juices.