Instant Pot Potatoes Au Gratin: A Weeknight Miracle

There are certain dishes that evoke pure comfort, and for me, potatoes au gratin is undeniably one of them. I remember my grandmother making it for Sunday dinners, the scent of bubbling cheese and tender potatoes wafting from the oven, a promise of pure bliss. The laborious process of thinly slicing potatoes and layering them with rich cream felt like an ancient ritual, a testament to love and patience. But let’s be honest, in our fast-paced lives, who has that kind of time for a weeknight meal? That’s where this Instant Pot version truly shines, transforming a labor of love into a remarkably quick and impossibly delicious reality.

Recipe Overview

• Prep Time: 15 minutes
• Cook Time: 10 minutes
• Total Time: 25 minutes (plus natural release time, if applicable)
• Servings: 6
• Yield: 1 casserole dish
• Dietary Type: Vegetarian

Ingredients

This recipe relies on simple, classic ingredients that come together harmoniously.

• 1 cup water
• 3 medium russet potatoes, peeled and very thinly sliced (about 1/8-inch thick)
• 1/2 cup chicken broth
• 1/2 cup evaporated milk
• 1/4 cup heavy cream
• 1 garlic clove, minced
• 1/2 yellow onion, diced
• 1 cup shredded mozzarella cheese
• 1/2 cup grated Parmesan cheese
• 1 tablespoon chopped fresh chives, for garnish (optional)

Equipment Needed

• 6-quart or larger Instant Pot
• Wire trivet (that came with your Instant Pot)
• 7-inch round casserole dish
• Cooking spray or butter for greasing the dish
• Aluminum foil
• Broiler (optional, for browning)

Instructions

This method takes the magic of the Instant Pot and combines it with the familiar comfort of a beloved dish, delivering incredible flavor and texture in a fraction of the time.

1. In a large measuring cup or bowl, whisk together the chicken broth, evaporated milk, heavy cream, minced garlic clove, and diced yellow onion until thoroughly combined. Set this liquid mixture aside.
2. Place the wire trivet into your 6-quart or larger Instant Pot. Pour 1 cup of water into the inner pot, around the trivet.
3. Generously grease the inside of a 7-inch round casserole dish with cooking spray or butter. This will prevent sticking and ensure easy serving.
4. Now, it’s time to layer. Arrange the thinly sliced russet potatoes in the prepared casserole dish, overlapping them slightly.
5. Sprinkle about half of the shredded mozzarella cheese and half of the grated Parmesan cheese over the potato layer.
6. Pour half of the milk mixture over the cheese and potatoes.
7. Add another layer of the thinly sliced russet potatoes.
8. Sprinkle the remaining mozzarella cheese and Parmesan cheese over this second potato layer.
9. Pour the remaining milk mixture over the top, ensuring all the potatoes are at least partially submerged.
10. Once all ingredients are in the casserole dish, loosely cover it with aluminum foil. This prevents excess moisture from getting into the dish during the pressure cooking phase.
11. Carefully place the covered casserole dish onto the wire trivet inside the Instant Pot.
12. Secure the lid of your Instant Pot, ensuring the steam release valve is set to the seal position.
13. Select the Pressure Cook (or Manual) setting and set the cooking time to 10 minutes on High Pressure.
14. Once the cooking cycle is complete, carefully perform a quick release of the pressure by moving the steam release valve to the vent position. Be cautious of the escaping steam.
15. Once the float valve has dropped and it’s safe to do so, carefully remove the lid.
16. Using oven mitts, carefully lift the casserole dish out of the Instant Pot.
17. Remove the aluminum foil. At this point, the potatoes should be tender. You can test this by inserting a fork or knife into one of the thicker potato slices.
18. Optional Browning Step: If you desire a golden-brown, slightly crisp top, place the uncovered casserole dish under your oven’s broiler. Keep a very close eye on it, as it can brown quickly, and broil for 1-3 minutes, or until the top is beautifully golden.
19. Garnish the potatoes au gratin with fresh chopped chives just before serving.

Expert Tips & Tricks

• Uniform Slicing is Key: The most crucial step for even cooking is ensuring your potatoes are sliced very thinly and uniformly. A mandoline slicer is your best friend here, but a sharp knife and a steady hand will also work. If your slices are too thick, they may not cook through in the allotted time.
• Don’t Skip the Trivet: The trivet is essential for lifting the casserole dish out of the water bath, preventing the bottom from becoming soggy.
• Loosely Cover: The aluminum foil is important for preventing water from dripping into your gratin, but it shouldn’t be sealed tightly, allowing some steam to escape.
• Broiler Vigilance: If you choose to broil, please stay with your dish. The cheese can go from perfectly golden to burnt in a matter of seconds.
• Make-Ahead Potential: You can prepare the potato layers and pour the liquid mixture over them up to the point of placing them in the Instant Pot. Cover the dish tightly and refrigerate. When ready to cook, simply place it in the Instant Pot as directed and adjust the cooking time by adding a minute or two if the dish is chilled.

Serving & Storage Suggestions

This Instant Pot Potatoes Au Gratin is a fantastic side dish that pairs beautifully with roasted meats, poultry, or even a hearty vegetarian main like lentil loaf. Serve it piping hot, allowing the creamy, cheesy goodness to melt in your mouth.

Leftovers can be stored in an airtight container in the refrigerator for up to 3 days. To reheat, gently warm individual portions in the microwave or place the entire dish back into a moderate oven (around 350°F/175°C) until heated through. Be aware that the texture may change slightly upon reheating, as the creamy sauce can become a bit looser.

Nutritional Information

(Estimates per serving)

Nutrient	Amount per Serving	% Daily Value
Calories	244.1 kcal
Calories from Fat	108 kcal
Total Fat	12 g	18%
Saturated Fat	7.2 g	36%
Cholesterol	41.8 mg	13%
Sodium	340.8 mg	14%
Total Carbohydrate	22.9 g	7%
Dietary Fiber	2.5 g	10%
Sugars	1.6 g	6%
Protein	11.7 g	23%

Note: Nutritional values are estimates and can vary based on specific ingredients and brands used.

Variations & Substitutions

• Garlic Lovers: Feel free to add another clove of minced garlic to the milk mixture or even rub the casserole dish with a cut garlic clove before greasing.
• Herbaceous Notes: Instead of or in addition to chives, consider adding fresh thyme or rosemary to the liquid mixture for a more aromatic profile.
• Spicy Kick: A pinch of cayenne pepper or a dash of hot sauce in the milk mixture can add a pleasant warmth.
• Cheese Variations: While mozzarella and Parmesan are classic, feel free to experiment with Gruyere, cheddar, or a blend of your favorite melting cheeses.
• Dairy-Free/Vegan Option: This is where it gets interesting! For a dairy-free version, you can substitute the evaporated milk and heavy cream with full-fat coconut milk or a blend of unsweetened cashew and oat milk. Use a good quality vegan mozzarella and vegan Parmesan alternative. The texture might be slightly different, but the flavor can still be excellent.

FAQs

Q: Can I use regular milk instead of evaporated milk and heavy cream?
A: While you can, using a combination of evaporated milk and heavy cream contributes to a richer, creamier texture that holds up well during pressure cooking. Regular milk might result in a thinner sauce.

Q: My potatoes are still hard after 10 minutes. What did I do wrong?
A: The most common reason is that the potato slices were too thick. Ensure they are sliced to about 1/8-inch thickness. If they are still undercooked, you can pressure cook for an additional 2-3 minutes on High Pressure.

Q: Can I make this without an Instant Pot?
A: Absolutely! You can follow the traditional method of layering potatoes, cheese, and cream in a casserole dish and baking it in a preheated oven at 375°F (190°C) for about 45-60 minutes, or until tender and golden brown.

Q: How do I prevent the potatoes from turning brown before cooking?
A: As long as you keep them submerged in the liquid mixture, the potatoes should be fine. You can also add a tablespoon of lemon juice to the liquid if you’re concerned about browning.

Q: Is it okay to use Yukon Gold or red potatoes?
A: Russet potatoes are ideal because their starch content helps create a creamy sauce. Yukon Gold potatoes can work, but they are waxier and might not break down as much. Red potatoes are generally not recommended for au gratin as their waxy texture doesn’t yield the desired creamy consistency.

Final Thoughts

This Instant Pot Potatoes Au Gratin is a game-changer. It’s proof that you don’t need hours in the kitchen to achieve deeply satisfying, comforting flavors. It’s the perfect example of how modern appliances can elevate classic dishes, making them accessible for busy weeknights without sacrificing an ounce of deliciousness. So, go ahead, give it a try, and prepare to be amazed. I’d love to hear how it turns out for you, and what delicious mains you pair it with!