Pommes De Terre A La Boulangere - cooking recipe

Ingredients

3 tablespoons butter
1 tablespoon olive oil
4 onions
2 lbs potatoes, thinly sliced
salt and pepper, to taste
fresh thyme, leaves picked
2 cups beef stock

Preparation

Preheat the oven to 300 degrees F.
Melt half the butter with the olive oil in a saute pan, and gently fry the onions until soft and lightly golden, about 15 minutes.
Spread half the onions in the bottom of a casserole.
Lay a layer of sliced potatoes on top, season with salt and pepper, and scatter with thyme leaves.
Build another layer of onions, then a final one of potatoes, and finally pour over the stock.
Cover the pan with foil, and bake until all the liquid has been absorbed, 2 to 3 hours, removing the foil for the last hour if you like a crisp top.