Traditionally this Rhone valley dish is sautéed on the cooker, but here it is finished in the oven.


3 large onions, sliced
2 tbsp olive oil
50g unsalted butter
1kg medium potatoes, like Desiree or Maris Piper, peeled
2 tbsp finely chopped flatleaf parsley, plus extra to serve 
2 tbsp fresh thyme leaves, plus extra to serve if you like
2 garlic cloves, thinly sliced
salt and freshly ground black pepper


1. Put the sliced onions, garlic, olive oil and half the butter in a large frying pan. Cook over a low-medium heat until the onions are soft but not golden-brown yet – this might take up to 30–35 minutes.

2. Meanwhile bring a large pan of salted water to the boil. Slice the potatoes into 5mm thick slices. Once the water is boiling, add the potatoes and when the water has returned to the boil, set your timer for 3 minutes. Drain immediately and leave in the colander to steam dry. 

3. When the onions are done, remove from the heat and stir through the parsley and thyme and season well. Gently toss the onion mixture and par-boiled potatoes together – you can do this in the frying pan if they fit, or a large mixing bowl.

4. Tip everything into a large baking dish – you don’t want the mixture to sit any deeper than 5cm. Arrange and press the top down a little to roughly flatten. Dot the remaining butter all over the top.

Heat the oven to 200°C/180°C/Gas 6.

5. Bake for 45 minutes, or until the potatoes are  cooked through. A little extra garnish of chopped parsley and fresh thyme is nice, but not strictly necessary.

NOTE: You can prepare up to Step 4 several hours in advance.