Mussels in Tomato Vinaigrette

I particularly like these mussels with their astringent dressing - an ice-cold beer would be the perfect accompaniment.

Ingredients
750g/1lb 10oz large, rope-grown mussels
1 medium vine-ripened tomato, skinned, roughly chopped
1 tbsp sherry vinegar
3 tbsp extra virgin olive oil
salt and freshly ground black pepper
1 tbsp capers, roughly chopped
2 pickled cornichons (mini gherkins), finely chopped
1 tbsp finely chopped red onion
1 tbsp finely chopped green pepper
1 tbsp finely chopped red pepper
1 tbsp finely chopped flatleaf parsley

Preparation method
Wash the mussels in plenty of cold water and scrape off any barnacles with a knife. Discard any that don’t show signs of closing when squeezed gently, then pull out the tough fibrous beards protruding from between the closed shells.
Heat a large, heavy-based pan over a high heat. Add the mussels and two tablespoons of water, cover and shake around for 2-3 minutes, or until the mussels have just opened. Drain into a colander and leave until cool enough to handle. (Discard any mussels that do not open.)
Break away the empty, top half-shell from each mussel. Release the meat in the other shell, but leave it in place. Place them side by side on a serving platter.
For the dressing, put the chopped tomato into a mini food processor and blend until smooth. Add the vinegar, oil and some salt and pepper to taste and blend briefly once more to combine.
Tip into a small bowl and stir in the capers, cornichons, red onion, green pepper, red pepper and parsley. Spoon some of the dressing over each mussel and serve at room temperature.
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