When I was a child, my mother often made onions in white sauce to serve with roast lamb. I loved their thick, velvety texture and how they brought richness, sweetness and even more savouriness to a good Sunday lunch. A similarly thick tangle of onions features in the classic soupe à l’oignon gratinée, which can’t really be mimicked without a deep, dark, beefy stock, so rather than even try, it’s best to introduce another layer of flavour entirely. The parsley here yields a very different end result that also proves to be rather comforting.
