Gratin DauphinoisGratin dauphinois
Thin slices of potato, laid in tight rings, and baked low and slow in warm cream until the outside holds a faint golden crust and the inside has gone soft enough to fall apart on the spoon. France's classic potato side, and the one where the slice is the technique: thick slices are a boiled potato, thin ones are a gratin.
Technique notes
The whole dish comes down to the slice. Cut the potato thin — about 3 mm (⅛ inch), and a mandoline makes it easy — and lay the slices in a tight overlapping ring, and the cream goes under and around them, not on top. Baked low, the cream simmers rather than boils, and the heat is what softens the potato from the outside in while the thin slices lend their starch to the cream, and it is that starch that takes the cream from a loose liquid to the thick body a gratin should have. Baking it low and long enough and the crust on top goes from cream-white to a faint gold, and the dish comes out with a crust on it and a soft middle under it. So the dish is a low, slow bake, a thin slice, and a cream that ends up thick enough to spoon rather than pour. Cut thick, and it is a boiled potato. Cut thin, and it is a gratin.
Equipment
- A deep, round, ovenproof dish, about 23 cm (9-inch), with straight sides
- A mandoline, or a sharp knife and a steady hand
- A measuring jug, for the cream
Ingredients
- 1 kg (2 lb) starchy white potato — a Yukon Gold or the like — peeled or unpeeled, sliced to 3 mm (⅛ inch) thick
- 500 ml (2 cups) double (heavy) cream
- 4 cloves of garlic, sliced into thin rounds
- 2 tbsp (30 g) unsalted butter
- 1 small thyme sprig, optional, for the cream
- ¼ tsp freshly grated nutmeg
- 1 tsp fine salt, plus more to taste
- A small pinch of freshly ground white pepper
Method
- Warm the cream with the garlic. Into a saucepan, over a low heat, put the cream, the sliced garlic, the thyme, the nutmeg, and ½ tsp of the salt, and heat it until it is just starting to shimmer — warm, not boiling. Pull it off the heat and let it sit for about 5 min, so the garlic and the nutmeg can get into the cream.
- Layer the potato in tight, overlapping rings. Butter the dish, and lay the first slices in a single layer, overlapping them about 2 mm at one side, and continue in layers until all the potato is in and the top layer is a flat, even surface. The slices should overlap and not stand on their ends, and the whole layer should be a tight, even disc from side to side of the dish.
- Pour in the cream, and bake it low and slow. Pour the warm cream over the layer, and press the top-down slice into it, so the cream comes right up to the surface. Dot the top with the butter, and cover the dish in foil. In a 160°C / 320°F oven, bake it for about 45 min, until the potato is soft to the touch and the cream is thickened with the starch of the potato. Then pull the foil off, and let the last 15 min be for the crust: the top should go from a cream-white to a faint, even gold, and the crust is what makes it a gratin rather than a pudding.
- Rest it, and then serve it. Let it sit for about 10 min, and the cream will set to the point where it holds on the spoon. Taste it for the remaining salt, and serve it in a wide, shallow dish, or scoop it onto the plate in a thick, even piece.
Common failures
- The cream has split to a separate, yellow pudding at the edge. The temperature was too high, and the cream boiled instead of simmered, and the fat came out of the curd. Bake it at 160°C / 320°F, and let the cream go from a shimmer to a still cream rather than a boil, and the cream stays a single, even body under a golden top rather than splitting into a yellow pudding at the edge.
- The middle is raw, and the slice is firm on one side and soft on the other. The slices are too thick, and the heat has not had time to get to the middle in the time it takes to go soft at the surface. Cut the potato to 3 mm (⅛ inch), and give it the full 45 min, and the middle will be as soft as the top.
- The layer has stuck to the dish, and the slice is broken where you lifted it off. The slices did not break down into the cream, because they were cut thick and the bake was too short. Cut them to 3 mm, and give the dish its full hour; a gratin comes out as one piece, and a pile of separate slices is a pudding that is not holding.
Variations & substitutions
- With a cheese on the top — the crust becomes a golden one. Put 50 g of Comté, Gruyère, or a firm Cheddar over the top, and the cheese will melt into the crust and make the crust a golden, crumbly one.
- With a cauliflower instead of the potato. Cut the cauliflower into small florets of the same size, and let it take the cream in the same bake. The gratin is a lighter one, and the crust on top is the same.
What to serve with it
A gratin dauphinois is a side: the way a piece of steak wants brown butter over it, or a poultry wants a sauce, the dish is a side, and it is the thing that carries the whole sauce of the plate. It is the starch of the plate, and it goes with a piece of meat, a piece of fish, or a little piece of cheese that is aged.
More
Back to French · Techniques (knife skills, braising, brown butter)