Preheat the oven to 200C/400F/Gas 6.
To make the crostini, heat a small frying pan. Add the lemon juice and grated radish and sauté for 2 minutes. Add the duck and basil and cook for a further few minutes.
Heat a griddle pan until smoking. Slice the ciabatta in half horizontally, drizzle with the oil and season with salt and freshly ground black pepper. Chargrill for 1 minute on each side, then place the warm radish mixture on the ciabatta slices and garnish with parsley.
For the feta salad, mix together the olive oil and lemon juice in a large bowl. Toss in the lettuce, feta, chervil, duck and radishes. Season with salt and freshly ground black pepper.
Serve the crostini on a plate with the salad.