Preheat the oven to 180C/355F/Gas 4.
Season the duck breast with salt and pepper. Heat the oil in a pan over a high heat and sear the duck for a few minutes minutes.
Transfer to the oven and cook until medium, 10-15 minutes. Allow to rest for ten minutes.
Meanwhile, chop the spring onions into julienne and chop the cucumber into thin batons.
Take the baby gem leaves and spread a little peanut sauce into each one.
Slice the duck into nice thin slices. Place two slices into each baby gem leaf and add a little spring onion and cucumber.
Sprinkle with peanuts and serve.