Wash the mussels in 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.
Soak the salt cod in 3 - 4 litres of water in the fridge for 24 - 48 hours, depending on thickness. Change the water several times.
Put the piece of soaked salt cod into a pan of cold water, bring to the boil, then cover and turn off the heat. Leave to sit for 10 minutes, then lift carefully onto a plate and leave to cool. Break into flakes, discarding the skin and any bones, cover and set to one side.
Whisk the ingredients together for the dressing with half a teaspoon of salt in a small bowl. Put the flaked salt cod, orange segments, onion rings and olives into a mixing bowl and pour over the dressing. Add the parsley and mix together gently. Leave for five minutes then adjust the seasoning to taste.
Lift the salad out of the excess dressing onto serving plates, garnish with the hard-boiled egg and serve at room temperature.
For the salsa brava, heat the olive oil over a low heat, add the pimentón, chilli flakes, Tabasco and vinegar and mix together well. Stir in the tomato sauce and season to taste with salt and freshly ground black pepper (thin the mixture with a little water if necessary).
Cut the potatoes into small, even-sized pieces. Drop into a large pan of well-salted water and cook for 6-7 minutes, or until just tender. Drain well.
Heat the olive oil in two large, non-stick frying pans, divide the potatoes between them and shallow-fry in a single layer for 10 - 12 minutes, turning them regularly, until crisp, golden-brown all over and sandy in texture.
Spoon the potatoes into one large or small individual serving plates, drizzle over the sauce, sprinkle with a pinch of pimentón and serve with some toothpicks and napkins.