For the picked cucumber, place the cucumber in a bowl. In a small saucepan, heat the rice vinegar with the sugar, chilli and ginger. Once the sugar has dissolved, strain over the cucumber and set aside to cool.
For the herb vinaigrette, blend the herbs, anchovies, lemon juice, capers and Dijon mustard in a food processor. With the motor running, gradually the olive oil until combined - the vinaigrette should have a spreadable consistency. Season to taste with salt and freshly ground black pepper.
For the sea bream, using a sharp knife, thinly slice the fillets on a diagonal. In a saucepan, gently fry the shallots and garlic in olive oil without colouring. Add the wine and then the clams. Cover with a lid and cook for three minutes, then drain in a colander. Remove the clam meat from their shells and finely slice.
To serve, divide the slices of sea bream between serving plates. Spread over the herb vinaigrette and dress with the clams and pickled cucumber.