Trim the duck breast and remove any excess sinew. Score the skin lightly with a sharp knife.
Put the peppercorns in a pestle and mortar and crush.
Roll each duck breast in the peppercorns then season to taste with salt.
Heat a frying pan until hot then add the vegetable oil and the duck breasts, skin-side down.
Cook for about one minute then reduce the heat and cook for about five minutes on each side, or until cooked to your own liking. (This amount of time will give you medium-rare meat.)
Remove the duck from the pan and rest on a wire rack over a plate.
To make the dressing, place the cherries and elderflower cordial into a saucepan and bring to a gentle simmer. Do not boil - just let the cherries warm through and bleed their colour into the cordial until it takes on a pink colour.
Remove the saucepan from the heat and allow the mixture to cool.
Remove the cherries from the mixture and set them aside.
Whisk in the cider vinegar and rapeseed oil. Add a pinch of salt to taste and return the cherries to the pan.
To serve, place the lettuce leaves, lovage and cress into a bowl and add a little of the dressing.
Cut the duck breasts into thin slices. Layer the salad and duck onto a plate. Spoon some more dressing around the outside of the salad and finish off with a sprinkling of the elderflower petals.