For onion relish, dice the onion. Sauté them in a pan with a bit of olive oil over low heat. Add the sugar, salt and pepper and stir regularly for 15 minutes. Set aside to cool.

Meanwhile, place the cabbage leaves in boiling water to blanch for 5 minutes. Drain them and put aside. Cut the foie gras slices into two. Season with salt and pepper and place a piece on each cabbage leaf. Tie up each parcel with a chive stem and steam them for 5 minutes. Serve each parcel with a spoonful of onion relish.