Erdäpfelgratin

Ingredients

Equipment Needed

• •Shallow baking dish (approximately 28cm x 20cm)
• •Mandoline or sharp knife
• •Medium saucepan
• •Aluminum foil

Instructions

1. 1

   Prepare the dish

   Preheat your oven to 170°C (340°F). Take one garlic clove, halve it, and rub the cut side all over the inside of a shallow baking dish, about 28cm by 20cm. Press firmly. You want the garlic oils in every corner. Then coat the entire inside with the softened butter. This does two things: it keeps the potatoes from sticking, and it gives the edges a golden, almost nutty crust where the cream bakes against the butter.

2. 2

   Warm the cream

   Pour the cream and milk into a saucepan. Add the minced garlic, the salt, the white pepper, and the nutmeg. Set it over low heat and bring it just to the point where tiny bubbles appear at the edges. Don't let it boil. You're warming the cream to dissolve the salt and wake up the garlic, not cooking it. Take it off the heat and let it sit while you slice the potatoes. The garlic will steep gently and give you a deeper, rounder flavor than raw garlic ever could.

   White pepper, not black. Black pepper leaves visible dark specks in the cream and a sharper bite than you want here. White pepper does its work quietly. The Viennese appreciate subtlety in a gratin.
3. 3

   Slice the potatoes

   Slice the peeled potatoes into rounds about three millimeters thick. A mandoline makes this easy, but a sharp knife and steady hand work fine. Consistency matters. If some slices are thick and some thin, the thin ones will dissolve into paste while the thick ones stay crunchy. Three millimeters. Not five. Not two. You want slices thin enough to cook through and absorb the cream, but sturdy enough to hold their shape as layers.

   Don't rinse the sliced potatoes. I know some recipes tell you to soak them in water. For a gratin, you want that potato starch. It thickens the cream as the dish bakes and gives you a sauce that clings to each layer instead of pooling at the bottom.
4. 4

   Layer the gratin

   Arrange a layer of potato slices across the bottom of your prepared dish, overlapping each slice by about a third. Think of fish scales. Pour a few spoonfuls of the warm cream mixture over the first layer, just enough to coat. Repeat: potatoes, cream, potatoes, cream. You want three to four layers, finishing with a neat layer of potatoes on top. Pour the remaining cream evenly over everything. The liquid should come about three-quarters of the way up the potatoes. If it doesn't reach that level, add a splash more milk. The potatoes need to be mostly submerged to cook evenly.

5. 5

   Bake covered

   Cover the dish tightly with aluminum foil and place it on the middle rack of the oven. Bake for forty-five minutes. The foil traps moisture so the potatoes steam in the cream and cook through completely before you ask the top to brown. If you skip the foil and go straight into an uncovered bake, the top layer turns leathery while the center stays raw. Patience here. Forty-five minutes, covered.

6. 6

   Brown the top

   Remove the foil. If using cheese, scatter it evenly across the surface now. Return the dish to the oven, uncovered, and bake for another twenty to twenty-five minutes. The cream will bubble up at the edges, thick and golden, and the top layer of potatoes will turn deep brown in spots. You're looking for a color somewhere between honey and chestnut. When you press the center gently with a spoon, the potatoes should yield without resistance.

   If the top is browning too fast before the center is tender, cover it loosely with foil again and keep baking. Every oven is different. Trust the texture of the potatoes, not the clock.
7. 7

   Rest and serve

   Pull the gratin from the oven and let it rest for ten to fifteen minutes on the counter. This is not optional. The cream, which is boiling and liquid right now, needs time to be absorbed back into the potato layers. If you cut into it immediately, it runs everywhere and you lose the structure. After fifteen minutes, the slices hold together when you serve them, the cream has thickened into a silky sauce between each layer, and the edges have that gorgeous golden crust where the cream reduced against the butter. Serve it straight from the dish. Mahlzeit!

Chef Tips

• •Use waxy potatoes, not floury ones. In Austria we'd reach for Kipfler or Ditta. Outside Austria, look for Yukon Gold or Charlotte. Floury potatoes like Russets fall apart in the cream and you end up with a thick porridge instead of distinct layers. The waxy varieties hold their shape and give you that beautiful layered cross-section when you cut into the dish.
• •Grate the nutmeg fresh from a whole nut. Pre-ground nutmeg tastes like sawdust by comparison. You only need the smallest amount, a few passes across a fine grater, but the difference is immediate. Gretel always said nutmeg should whisper, not shout.
• •The cheese is optional and there are strong feelings about this in Austria. A traditional Erdäpfelgratin from Vienna often has no cheese at all, just cream and potatoes. In Salzburg and the Alpine regions, a handful of Bergkäse or Emmentaler on top is common. Both versions are correct. Make the one that speaks to you.
• •This gratin reheats beautifully the next day. Cover it with foil and warm it at 150°C for twenty minutes. The cream tightens up overnight, and the leftovers are almost better than the original. Almost.

Advance Preparation

• •The cream can be warmed and infused with garlic up to a few hours ahead. Keep it covered at room temperature and reheat gently before assembling.
• •The fully assembled gratin can be prepared up to the point of baking and refrigerated, covered, for up to four hours. Add five to ten minutes to the covered baking time if going straight from fridge to oven.
• •Leftover gratin keeps well in the fridge for two days. Reheat covered at 150°C until warmed through.

Frequently Asked Questions

Nutrition Information

1 serving (about 275g)