Tartiflette is a classic French dish traditionally made with potatoes, cheese, lardons and onions. For this French-onion tartiflette, we’ve left out the potatoes to make it a lighter version.
Every home cook needs this ridiculously easy classic in their repertoire. The trick to that timeless earthy flavour is to cook your onions on a very low heat, slowly. This may take some time, but it will be worth it. Make sure they get some nice dark colour, just short of burning, for a perfectly rich French onion soup.