Lyonnaise potatoes are one of those French bistro sides that make steak dinners feel “restaurant-level” at home. Thin potato slices, slowly browned in duck fat or butter, sweet onions cooked just enough to melt, then a shower of fresh parsley — simple ingredients, but technique matters. This version is optimized for North American home kitchens (Canada/USA), with clear steps so you get tender potatoes that hold their shape, light browning, and no soggy texture.

You can serve this as a side to a good steak like Steak au poivre (easy French pepper steak), any sauced meat such as Creamy mushroom sauce for steak, Duck confit, French classic, or even next to a bowl of Classic French onion soup for a full bistro-style menu. If you already make his Homemade garlic butter, that’s an easy finishing touch.

Why this version works

We parboil the potatoes briefly so they cook evenly and don’t break.
We cook the onions separately so they caramelize instead of steaming.
We finish in the pan or oven to set the texture.
We include duck fat for flavor, but give substitutions.
It’s written to pair with your other French main dishes and sauces on the blog (steak, duck, roasts).

Ingredients

800g (1.75 lb) waxy or yellow potatoes, peeled, sliced 3–4 mm (⅛–¼ in)
300g (10.5 oz) yellow onions, thinly sliced (about 2 medium)
40g (3 tbsp) duck fat (or clarified butter or neutral oil + 1 tbsp butter)
20g (1.5 tbsp) butter
30g (2 tbsp) fresh parsley, finely chopped
5g (1 tsp) fine salt, plus more to taste
2g (½ tsp) freshly ground black pepper
30ml (2 tbsp) chicken stock or water to deglaze, optional
5ml (1 tsp) lemon juice or a few drops of vinegar, optional, for brightness

Step-by-step method

1. Parboil the potatoes

Bring a large pot of salted water to a boil.
Add the sliced potatoes and cook 2–3 minutes only.
Drain and let them steam-dry on a tray.

2. Cook the onions separately

In a large sauté pan, heat 10g (2 tsp) duck fat over medium.
Add the onions, a pinch of salt, and cook 8–10 minutes until soft and lightly golden.
Transfer to a bowl and keep warm.

3. Brown the potatoes

In the same pan, add the remaining duck fat and butter.
Lay the potatoes in a single, slightly overlapping layer.
Season with salt and pepper.
Brown 4–5 minutes per side without moving too much.

4. Deglaze (optional)

Add 2 tbsp chicken stock or water and scrape the browned bits — like when you make Homemade tomato sauce with fresh tomatoes, the fond gives flavor.

5. Combine and finish

Add the cooked onions back.
Toss gently.
Add chopped parsley.
Adjust seasoning.
Optional: finish 5–7 minutes in 350°F / 180°C oven to set.

Substitutions and variations

Duck fat → butter + oil.
Onions → shallots.
Parsley → chives.
For steak nights → finish with a spoon of Homemade garlic butter.
For a big French menu → serve with Crispy homemade Belgian fries for a “duo de patates”.

FAQ

Can I make this ahead?
Parboil potatoes and cook onions ahead; do browning and parsley right before serving.

Why are my potatoes soggy?
They weren’t dried after boiling or you added onions too early.

Can I use russets?
Yes, but they break more easily — stick to yellow/waxy if you can.

What do I serve it with?
Any steak or sauced chicken — try Creamy mustard chicken with mushrooms or Chicken piccata.

What to serve with (suggested posts)