You know a cooking method is a classic when it’s named after a city. Lyonnaise cuisine, from Lyon, France, has this wonderful way of being both rustic and incredibly sophisticated, all at once. This dish is a perfect example—it transforms the humble green bean with the deep sweetness of slow-cooked onions and the sharp, wake-up-call tang of vinegar. It’s a side that commands attention.
Quick Look
| Prep | Cook | Total | Feeds | Level |
|---|---|---|---|---|
| 15 min | 25 min | 40 min | 4 | Simple, but requires patience |
Grab These
- 1 lb haricots verts, ends trimmed
- 2 tbsp unsalted butter
- 1 large yellow onion, halved and thinly sliced
- 2 tbsp red wine vinegar
- 1 tbsp fresh parsley, chopped
- Salt and freshly ground black pepper
Let’s Make It
This whole recipe rests on the onions, so let’s give them the love they deserve. Melt the butter in a large skillet over medium-low heat. Add the sliced onions and a generous pinch of salt. Now, walk away. Well, not entirely, but you need to let them cook low and slow for a good 15-20 minutes, stirring only occasionally. You’re waiting for them to become a soft, tangled, golden-brown mess. No shortcuts here.
While the onions are caramelizing, blanch your beans. Get a pot of well-salted water boiling and cook the haricots verts for 3-4 minutes, until they’re just tender-crisp. Drain them and immediately give them an ice bath to stop the cooking. This locks in that gorgeous color and perfect snap.
Once your onions are perfectly golden and smell amazing, it’s time for the grand finale. Increase the heat to medium-high and pour in the red wine vinegar. It will hiss, steam, and sizzle violently—this is good! You’re deglazing the pan, scraping up all the flavorful browned bits from the bottom.
Drain your beans thoroughly and add them to the skillet. Toss everything together for a couple of minutes until the beans are heated through and beautifully coated in the tangy onion jam. Finish with the fresh parsley and a very generous amount of black pepper.
My Two Cents
- Calories: About 90 per serving
- Storage: Best served immediately, but leftovers will keep for a day in the fridge.
- Swaps: A splash of white wine instead of vinegar adds a different kind of brightness.
- Pro-Tip: For an extra layer of flavor, use bacon fat instead of butter. It adds a smoky depth that is just incredible.
You Asked, I’m Answering
Q: Can I use a sweet onion instead of a yellow onion?
- A: You can, but yellow onions have a better balance of sugar and sharpness for caramelizing. Sweet onions can become too soft and sweet.
Q: My vinegar smell is so strong! Is that normal?
- A: Yes! The sharp aroma mellows dramatically as it cooks and melds with the butter and onions, leaving behind a beautiful, nuanced tang.