Preheat an oven to 180c /350f /gas mark 4.
Spread the bread cubes in baking dish and bake in the preheated oven until crisp and golden. Remove from the oven.
Add olive oil, vinegar, garlic, basil leaves and salt in a food processor and blend at high speed for a few seconds to make a coarse paste.
Add the bread cube, chicken, tomatoes and cucumbers and toss well.
Let the salad stand for a minutes. This allows the bread to soften slightly.
Line a serving dish with lettuce leaves and transfer the salad into it. Garnish with basil leaves and serve immediately.