- 1½ kg King Edward potato, Desiree, or similar, peeled
- 1 onion, finely chopped
Onions are endlessly versatile and an essential ingredient in countless recipes. Native to Asia…
- knob of butter, plus extra for greasing
Butter is made when lactic-acid producing bacteria are added to cream and churned to make an…
- 100ml white wine
- 300ml milk
One of the most widely used ingredients, milk is often referred to as a complete food. While cow…
- 400ml double cream
- 3 sage leaves, finely chopped
Popular in both Italian and British cookery, sage has long, grey-green leaves with a slightly…
- 50g gruyère, grated
Gruyère is an undoubted pinnacle of traditional Swiss cheese-making, a culinary masterpiece as…
Heat oven to 190C/170C fan/gas 5. Boil the potatoes for 3 mins to soften a little, then drain. When cool enough to handle, slice into 5mm pieces. Cook the onion in the butter in a pan until softened, about 5 mins, then pour over the wine, milk and cream and heat through. Place the potato slices into a large bowl, pour over the cream mixture, sage leaves and half the cheese. Carefully stir until the potato slices are coated.
Grease a large baking dish (about 20 x 30cm) with a little butter, then tip the potatoes in. Smooth over the top, scatter over the remaining cheese and season with black pepper. Cover with foil and cook for 30 mins, then uncover and cook 30-40 mins more until a fork slides in easily and the top is golden brown.
Prepare aheadThe bake can be layered ready to bake up to 1 day ahead. Keep it in the fridge covered and give it 10 mins more in the oven if cooking from cold.