Ingredients
Method
1.Preheat the oven to 180°C. Generously coat a large ovenproof dish with some of the butter.
2.Layer half of the potatoes in the dish and sprinkle over the [sliced onions](https://www.foodtolove.co.nz/5-tips-for-cutting-onions-without-crying-1879|target=”_blank”). Scatter the sage leaves over and season with pepper. Add the remaining potatoes and dot with butter.
3.Mix together the cream, [stock](https://www.foodtolove.co.nz/recipes/vegetable-stock-16879|target=”_blank”) and mustard, then pour over. The liquid level should come about ¾ of the way up the potatoes in the dish, but this will depend on your dish size.
4.Cover tightly with foil and bake in the preheated oven for 1 hour or until the potatoes are tender. Remove the foil for the remaining 10 minutes of cooking so that the top turns golden. Leave to sit for 10 minutes before serving.
We tend not to season this dish with salt as the stock will likely be salty enough.
Note
