|DICASTIO|

If you enjoy scalloped potatoes but want a rich cheesy topping, make au gratin potatoes. Layers of thinly sliced potatoes cooked in a baking dish or slow cooker with heavy cream or a rich cheese sauce over them, sprinkled with cheese until the potatoes are tender and the topping is bubbly. For a sophisticated flavor, you can also sauté sliced fennel with onion to layer in between the potatoes. Top the gratin with Gruyère cheese and cook it until the cheese is browned. The instructions tell you exactly how to make this delicious side dish or light meal.

[Edit]Ingredients

[Edit]Au Gratin Potatoes with Gruyère

2½ pounds (1.1 kg) yukon gold potatoes
1 tablespoon (14 g) butter
1½ cups (355 ml) heavy cream
1 cup (240 ml) whole milk
¼ teaspoons (0.5 g) freshly grated nutmeg
Coarse salt and freshly ground pepper
3 ounces (85 g) Gruyère cheese, shredded

Makes 6 servings

[Edit]Slow Cooker Au Gratin Potatoes

5 to 6 potatoes
½ cup (75 g) onion, minced
3 tablespoons (42 g) butter
3 tablespoons (24 g) flour
2 cups (475 ml) milk
4 ounces (115 g) smoked gouda, shredded
4 ounces (115 g) sharp cheddar, shredded
3 tablespoons (15 g) parmesan cheese, grated
Salt and pepper to taste

Makes 4 to 6 servings

[Edit]Potato-Fennel Gratin

1/2 teaspoon (1 g) freshly ground black pepper
2 small fennel bulbs
1 yellow onion, thinly sliced
2 tablespoons (30 ml) olive oil
1 tablespoon (14 g) unsalted butter, plus more for greasing the dish
4 Russet potatoes
2 cups (475 ml) plus 2 tablespoons (30 ml) heavy cream, divided
2 1/2 cups (270 g) grated Gruyère cheese, divided
1 teaspoon (5 g) kosher salt

Makes 10 servings

[Edit]Steps

[Edit]Au Gratin Potatoes with Gruyère

Preheat the oven to and grease a baking dish. Get out a 9 x 12-inch (22 x 30-cm) baking dish and rub 1 tablespoon of butter over the bottom and insides to prevent the potatoes from sticking. Set the dish aside while you prepare the potatoes.^[1]
Peel and soak the potatoes. Rinse 2½ pounds (1.1 kg) of yukon gold potatoes and peel the skins. Discard the potato peels and place the peeled potatoes into a large bowl. Fill the bowl with cold water and let the potatoes soak while you make the cream sauce.^[2]
- Soaking the potatoes will prevent them from becoming discolored as they sit.
Heat the cream, milk, nutmeg, and salt. Pour 1½ cups (355 ml) of heavy cream into a saucepan along with 1 cup (240 ml) of whole milk, ¼ teaspoons (0.5 g) of freshly grated nutmeg, 1 1/2 teaspoons (8 g) of salt, and freshly ground pepper to taste. Turn the burner to medium and stir the liquid occasionally until it starts to bubble around the edges. Turn off the burner.^[3]
Slice the potatoes -thick. Lift the soaked potatoes out of the bowl of water and set them on a cutting board. Use a mandolin or a knife to slice each potato into -thick slices. Pour the water out of the bowl and wipe it dry with a kitchen towel. Pat the potato slices dry and place them into the bowl.^[4]
Mix the potato slices with the cream mixture. Once you've sliced all of the potatoes and put them in the bowl, slowly pour the warm cream mixture over the slices. Use your hands or a spoon to toss the potatoes in the mixture so they're completely coated.^[5]
Transfer the potato mixture to the dish and sprinkle the cheese on top. Use the spoon to push the potato slices down. This way the cream should cover most of the potato slices. Scatter 3 ounces (85 g) of shredded Gruyère cheese evenly over the top of the potatoes.^[6]
Bake the au gratin potatoes for 1 hour and 15 minutes. Place the baking dish in the center rack of the preheated oven. Set a baking sheet on the rack that's underneath it to catch any drips. Bake the potatoes until they're soft when you insert and remove a fork. The cream mixture should bubble and the cheese will brown once it's finished cooking.^[7]
- If the potatoes are still firm, cook them for 15 minutes and check them again.
Serve the au gratin potatoes. Turn off the oven and let the au gratin potatoes sit for 5 to 10 minutes before you serve them. This will make it easier to handle them and the liquid will thicken a little as it cools. Serve the au gratin potatoes with sliced ham, greens, or roasted vegetables.^[8]
- Store the leftover au gratin potatoes in an airtight container in the refrigerator for 3 to 5 days.

[Edit]Slow Cooker Au Gratin Potatoes

Grease the slow cooker. Spray the bottom and inside walls of a slow cooker with cooking spray. If you don't have cooking spray, you can rub butter to grease the slow cooker. This will prevent the potatoes from sticking.^[9]
- You'll need to use a slow cooker that's at least 4-quarts (3.8 liters) in size.
Peel and slice the potatoes. Rinse 5 to 6 potatoes and use a vegetable peeler to remove the peel. Use a sharp knife to slice the potatoes into slices.^[10]
Layer the potato slices with minced onion. Spread a layer of potato slices in the bottom of the slow cooker and sprinkle about 1/4 cup (37 g) of minced onions over it. Sprinkle salt and pepper according to your taste over the layer. Spread the rest of the potato slices evenly in the slow cooker and top them with the remaining 1/4 cup (37 g) of minced onions.^[11]
Cook the butter with the flour to make a roux. Place 3 tablespoons (42 g) of butter into a saucepan and turn the heat to medium. Once the butter melts, stir in 3 tablespoons (24 g) of flour and cook it for 1 minute. Stir the roux constantly so it thickens and becomes pale.^[12]
Whisk in the milk and cook the sauce for 3 to 5 minutes. Keep the heat on medium and slowly whisk in 2 cups (475 ml) of milk. Continue to whisk and cook the sauce until it thickens a little.^[13]
- Avoid boiling the sauce or it will curdle and burn on the bottom.
Turn off the heat and stir in the cheeses. Use a spoon to stir in 4 ounces (115 g) of shredded smoked gouda, 4 ounces (115 g) of shredded sharp cheddar, and 3 tablespoons (15 g) of grated parmesan cheese. Stir until the cheeses are dissolved in the sauce.^[14]
Pour the cheese over the potatoes and turn the slow cooker on to HIGH. The cheese sauce should almost cover the potatoes. Put the lid on the slow cooker and turn it on to HIGH.^[15]
Cook the potatoes on HIGH for 2 to 3 hours then on LOW for 1 hour. Change the heat back to HIGH and cook the potatoes for 2 to 3 hours so they're completely soft. Turn the slow cooker to LOW and cook them for 1 more hour.^[16]
- The total cooking time will be 3 to 4 hours.
Serve the slow cooker au gratin potatoes. Turn off the slow cooker and take the lid off. Serve the hot au gratin potatoes with roast beef, steamed vegetables, or rolls. Store the leftover potatoes in an airtight container in the refrigerator for 3 to 5 days.^[17]

[Edit]Potato-Fennel Gratin

Preheat the oven to and grease a baking dish. Get out a 10 x 15-inch (25 x 38-cm) baking dish and rub about 1 tablespoon (14 g) of butter over the inside. Greasing the baking dish will keep the potatoes from sticking.^[18]
Trim the fennel bulbs and slice them. Take 2 small fennel bulbs and cut off the stalks that poke out from the bulbs. Use a sharp knife to cut the bulbs in half lengthwise. Use a paring knife to cut out and remove the hard cores from each bulb. Slice the fennel bulbs into thin slices.^[19]
- You should have about 4 cups (348 g) of sliced fennel.
Sauté the fennel with the sliced onion for 15 minutes. Put 2 tablespoons (30 ml) of olive oil and 1 tablespoon (14 g) of unsalted butter into a saucepan and turn the burner on to medium-low. Stir in the sliced fennel and 1 thinly sliced yellow onion. Sauté the vegetables and stir them occasionally until they're soft and translucent.^[20]
Peel and slice 4 potatoes. Use a vegetable peeler to peel the Russets. Set them on a cutting board and cut them into slices. If you prefer, you can use a mandoline to evenly slice the potatoes. Transfer the potato slices to a large mixing bowl.^[21]
Toss the potato slices with cream, cheese, salt, and pepper. Pour 2 cups (475 ml) of the heavy cream over the potato slices and add 2 cups (216 g) of the grated Gruyère cheese. Sprinkle 1 teaspoon (5 g) of kosher salt and 1/2 teaspoon (1 g) of freshly ground black pepper in the mixing bowl. Use a large spoon to toss the ingredients until they're combined.^[22]
Stir in the sautéed vegetables and transfer the mixture to the baking dish. Mix in the sautéed fennel and onion so it's combined with the seasoned potato slices. Scoop the mixture into the greased baking dish and push down on the potatoes so they're submerged in liquid.^[23]
Mix and scatter the rest of the cream and cheese over the potatoes. Pour the remaining 2 tablespoons (30 ml) of heavy cream into a small mixing bowl. Add the remaining 1/2 cup (54 g) of grated Gruyère cheese and stir until they're combined. Sprinkle the mixture evenly over the potatoes in the baking dish.^[24]
Bake the potato-fennel gratin for 1 hour and 30 minutes. The potatoes should become completely soft and the cheese on the top will melt and bubble. Insert a fork to see if the potatoes have cooked enough. If the potatoes are too firm, cook the gratin for another 15 minutes and check again.^[25]
Rest the gratin for 10 minutes and serve it. Turn off the oven and remove the baking dish from the oven. Let the potato-fennel gratin sit at room temperature for 10 minutes. This will help the cheese set and the sauce firm up before you dish it onto serving plates. Serve the gratin with roasts, glazed vegetables, or crusty rolls.^[26]
- Refrigerate the leftovers in an airtight container in the refrigerator for 3 to 5 days.