Heat 2 tablespoons of the oil in a frying pan, add the bread and garlic and fry until crisp and golden. Transfer to a plate and allow to cool. Cover and set aside.
Cut the leeks into 2 or 3 slices, depending on their length, then steam them over a pan of boiling water for 3–4 minutes until just tender. Arrange the leeks in a salad bowl and sprinkle the chopped eggs over the top.
Beat the remaining oil with the vinegar, mustard and seasoning. Drizzle over the leeks and add the capers and parsley. Cover and chill until required.
When ready to serve, toss the salad gently and sprinkle with the croûtons. Spoon on to serving plates and serve immediately.