Mashed Potato Casserole

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If there’s one dish that consistently earns praise at my dinner table, it’s this Mashed Potato Casserole. Creamy, buttery mashed potatoes baked to golden perfection and topped with a sprinkle of fresh herbs—this dish brings all the comfort of traditional mashed potatoes, but with a bit more structure and richness. I’ve made it for holidays, weeknight meals, and potlucks, and it never fails to impress.

What I love about this casserole is its versatility. You can dress it up with cheese and crispy bacon, or keep it simple and elegant with just chives and a touch of cream. The best part? It’s make-ahead friendly, so it reduces stress when you’re cooking for a crowd. Whether you’re serving it with roasted meats or as part of a vegetarian feast, this dish holds its own.

Why You’ll Love This Mashed Potato Casserole

This casserole is comfort food with a little upgrade. The mashed potatoes are whipped until velvety smooth, mixed with sour cream and butter for richness, then baked until slightly crisp around the edges. It’s cozy, crowd-pleasing, and ideal for both special occasions and casual dinners.

• Great for feeding a crowd
• Make-ahead and freezer friendly
• Adaptable to different flavors and toppings
• Golden top with soft, creamy inside
• Pairs well with many main dishes

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What Kind of Potatoes Should I Use?

For ultra-creamy results, I always go with Yukon Gold or Russet potatoes. Russets are starchy and yield the fluffiest texture, while Yukon Golds have a naturally buttery flavor and smooth consistency. You can even use a mix of both for the best of both worlds.

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Options for Substitutions

Not a fan of sour cream? Swap it with cream cheese or Greek yogurt for a tangy twist. Want it dairy-free? Use olive oil and unsweetened almond milk. Cheddar, Gruyère, or Parmesan can replace the classic butter topping. And if you’re aiming for a low-carb version, try cauliflower mash instead of potatoes.

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Ingredients for this Mashed Potato Casserole

• Russet or Yukon Gold Potatoes – These are the best for mashing, giving a creamy texture that holds up well in a casserole.
• Butter – Adds richness and that classic comfort food flavor.
• Sour Cream – Brings a slight tang and creamy consistency.
• Milk – Helps thin out the mash just enough for a velvety smooth finish.
• Cream Cheese – Optional, but makes the potatoes ultra-luxurious.
• Salt & Pepper – Essential for bringing out all the flavors.
• Garlic Powder or Fresh Garlic – For a savory depth.
• Shredded Cheese (Cheddar or Gruyère) – For a golden, gooey top layer.
• Chives or Green Onions – Fresh garnish that adds a pop of color and a subtle bite.

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Step 1: Peel and Boil the Potatoes

Peel your potatoes and cut them into evenly-sized chunks. Add them to a large pot, cover with cold water, and season generously with salt. Bring to a boil and cook until fork-tender, about 15–20 minutes.

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Step 2: Mash and Mix

Drain the potatoes well and return them to the pot or transfer to a large mixing bowl. Mash until smooth using a potato masher or hand mixer. Add butter, sour cream, milk, cream cheese (if using), garlic, salt, and pepper. Mix until fully combined and fluffy.

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Step 3: Assemble the Casserole

Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish. Spoon the mashed potatoes into the dish and spread evenly. If desired, top with shredded cheese for extra indulgence.

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Step 4: Bake to Perfection

Bake uncovered for 25–30 minutes or until the top is lightly golden and the edges are bubbling. If you added cheese on top, it should be melted and slightly crisp.

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Step 5: Garnish and Serve

Remove from the oven and let it rest for 5–10 minutes. Garnish with chopped chives or green onions. Serve warm and enjoy the creamy, dreamy goodness!

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How Long to Prepare the Mashed Potato Casserole

Prep Time: Most of your time will go into peeling, boiling, and mashing the potatoes. This takes about 30 minutes from start to finish, especially if you’re making a large batch. Using a hand mixer can speed things up.

Bake Time: Once assembled, the casserole needs 25–30 minutes in the oven. If you’re baking it from chilled (after prepping ahead), give it an extra 10–15 minutes to heat through evenly.

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Tips for Perfect Mashed Potato Casserole

• Warm your milk and butter before adding them to the mash to keep everything hot and creamy.
• Don’t over-mix the potatoes or they can turn gluey—mash until smooth, then gently fold in the ingredients.
• Use full-fat sour cream or cream cheese for the richest flavor.
• Let the casserole rest for 5–10 minutes after baking to firm up before serving.
• A sprinkle of paprika on top before baking adds color and a hint of warmth.

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Watch Out for These Mistakes While Cooking

• Undercooking the potatoes: They should be fork-tender; otherwise, the mash will be lumpy.
• Adding too much liquid: It can make your casserole watery. Add a little at a time.
• Skipping the seasoning: Don’t forget to season the boiling water and the mash itself.
• Over-mixing: This makes the potatoes gummy instead of fluffy.
• Not greasing the baking dish: The edges might stick and brown unevenly.

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What to Serve With Mashed Potato Casserole?

1. Herb-Crusted Roast Chicken

Perfectly complements the creamy texture of the casserole with its crispy skin and juicy meat.

2. Garlic Butter Green Beans

Adds freshness and a bit of crunch to balance the richness.

3. Balsamic Glazed Carrots

Sweet, tangy, and roasted to bring out their natural sugars.

4. Slow-Cooked Beef Brisket

The savory depth of the meat pairs beautifully with the smooth mashed potatoes.

5. Cranberry Sauce or Apple Chutney

For a fruity, acidic contrast that wakes up the palate.

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Storage Instructions

Refrigerator: Store leftovers in an airtight container for up to 4 days. Reheat in the microwave or oven until warm throughout.

Freezer: This casserole freezes beautifully. Assemble it in a freezer-safe dish, cover tightly, and freeze for up to 2 months. Thaw overnight in the fridge before baking. You may need to add an extra splash of milk when reheating to bring back the creaminess.

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Estimated Nutrition

Per serving (based on 8 servings):

• Calories: ~290 kcal
• Protein: 6g
• Carbohydrates: 32g
• Fat: 16g
• Saturated Fat: 10g
• Fiber: 2g
• Sugar: 2g
• Sodium: 320mg
• Cholesterol: 45mg

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Frequently Asked Questions

Can I make this ahead of time?

Absolutely! Assemble the casserole a day in advance, cover, and refrigerate. Bake it the next day, adding about 10–15 minutes to the cook time.

Can I freeze mashed potato casserole?

Yes. Prepare it fully (before baking), cover tightly, and freeze for up to 2 months. Thaw overnight in the fridge before baking.

What kind of cheese works best?

Cheddar is classic, but Gruyère, Parmesan, or even mozzarella can work depending on your flavor preference.

How do I prevent gummy mashed potatoes?

Avoid over-mixing and use starchy potatoes like Russets. Mash just until smooth.

Can I make this dairy-free?

Yes! Use plant-based milk, vegan butter, and a dairy-free sour cream or yogurt alternative.

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Conclusion

Mashed Potato Casserole is the ultimate comfort dish that brings people together. It’s creamy, rich, and endlessly customizable, making it suitable for holidays, weeknight dinners, or potluck gatherings. Once you try it, it just might become your go-to potato side forever. Whether you’re looking for a crowd-pleaser or a dish to prep ahead, this casserole has you covered.

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