How to reheat a gratin dauphinois made the day before without drying it out

To reheat a gratin dauphinois made the day before, take it out of the refrigerator 30 minutes beforehand, drizzle a few spoonfuls of cream over it, cover it with aluminum foil, and bake it at 150 °C for 25 to 45 minutes, depending on the size of the dish. Remove the aluminum foil for the last 10 minutes so the top can brown again.

Between you and me, a Dauphinois is often better the next day. When I have guests under the pergola, I cook it the night before, and on the big day, I don't have to rush around.

Tips for Reheating a Gratin

• In the oven, the best method: 150 °C, covered dish, 25 to 30 minutes for 4 servings, 40 to 45 minutes for a large dish that serves 8.
• In the microwave : Divide into portions, place on a covered plate, heat for 2 to 3 minutes on medium power with a spoonful of milk, then let stand for 1 minute.
• In a skillet : Cook the slices in a buttered skillet, covered and over low heat, for 8 to 10 minutes. The bottoms turn golden brown—they're a real treat.
• The Right Test : The center should be piping hot and steaming. Using a meat thermometer, aim for a core temperature of at least 63 °C.
• Preservation : Store in the refrigerator, covered, within 2 hours of cooking, and consume within 2 to 3 days. Reheat only once.

Ingredients for 8 people

• 2 kg of floury or mixed-type potatoes
• 1 liter of whole milk
• 40 cl of whole heavy cream, plus 10 cl for reheating
• 3 cloves of garlic
• 40 g of butter
• 20 g of fine salt
• 1/2 teaspoon grated nutmeg
• Freshly ground pepper

For 2 people, divide all the ingredients by four (500 g of potatoes, 25 cl of milk, 10 cl of cream) and reheat, covered, for 20 minutes at 150 °C.

Preparation: 30 min · Cooking: 1 hour and 15 minutes the day before, 45 minutes on the day of the event

The Step-by-Step Recipe

1. The day before, preheat the oven to 170 °C. Peel the potatoes and cut them into 3-mm-thick rounds, without rinsing them.
2. Rub a large baking dish (about 30 x 40 cm) with a clove of garlic cut in half, then butter it with 20 g of butter.
3. In a saucepan, bring the milk and 40 cl of cream to a simmer along with the other 2 crushed garlic cloves, salt, nutmeg, and pepper.
4. Arrange the slices in layers in the dish and pour the hot liquid over them: it should just cover them. Dot the remaining butter over the top.
5. Bake for about 1 hour and 15 minutes. Take it out when a knife inserts easily and the top is just lightly browned—it will finish browning when reheated.
6. Let it cool for up to 1 hour, cover it, and place it in the refrigerator.
7. On the day of the event, take the dish out 30 minutes beforehand. Pour the 10 cl of cream in a thin stream over the top and along the edges.
8. Cover with aluminum foil and bake for 35 minutes at 150 °C, then remove the foil and continue baking for 10 minutes to brown the top.

My Cooking Tips

• Don't prepare the gratin with raw ingredients the day before: the slices will turn brown and release water. If you don’t want to cook it all the way through, pre-cook them for 10 minutes in milk and cream, pour into the dish, let cool, and refrigerate; the next day, bake for about 1 hour at 160 °C.
• Cut the gratin into slices once it has cooled: the slices will be neat, and you can reheat just a portion of it.
• If the top has dried out a little, add a small pat of butter along with the cream before baking.
• To freeze, wrap the portions while they're very cold and store them for 2 to 3 months. Let them thaw overnight in the refrigerator, then reheat them in the oven: the texture will be just a little less melt-in-your-mouth.

Under the pergola: how to serve

On the big day, all you have to do is take care of the leg of lamb or roast, and a nice green salad. It’s no big deal, but when the gratin arrives at the table, golden and bubbling, everyone will think you spent the whole morning in the kitchen. A red wine from Palette or Bandol pairs well with it—to be enjoyed in moderation.

Your Questions

How do you reheat a gratin that's already been cooked?

The oven is still the best option: 150 °C, covered dish, with a splash of cream or milk. For a single serving, the microwave or a covered skillet are faster.

How can you reheat food in the oven without drying it out?

Three steps: a little liquid on top, aluminum foil for most of the cooking time, and a gentle temperature of 150 °C. You only uncover it at the end, to brown the top.

Can you make gratin dauphinois ahead of time?

Yes, it's actually recommended: cook it the day before, letting it brown just a little, and reheat it the next day. That gives the potatoes time to really soak up the cream.

How do you store a gratin dauphinois for the next day?

Let it cool to room temperature—but no longer than 2 hours—then cover it and put it in the refrigerator. It will keep for 2 to 3 days.

Can you reheat frozen gratin dauphinois?

Yes, after thawing overnight in the refrigerator, bake it in the oven at 150 °C covered with aluminum foil. If baking it straight from the freezer, allow at least twice as long, and make sure the center is thoroughly heated.