Make-Ahead Mashed Potato Casserole



Prep Time: 25 minutes
Cook Time: 45–50 minutes
Total Time: 1 hour 15 minutes
Servings: 10–12
Category: Side Dish

Notes After Making

Add

Ingredients

  • 3 pounds russet or Yukon Gold potatoes, peeled and cubed
  • ¼ cup butter, melted, plus more for greasing the baking dish
  • 1 cup sour cream
  • 2 large eggs, lightly beaten
  • ¼ cup finely diced onion
  • 1 teaspoon salt, or to taste
  • ½ teaspoon black pepper
  • ½ teaspoon garlic powder, optional
  • ½–1 cup shredded cheddar cheese, optional topping

Instructions

Prepare the Potatoes

  1. Preheat the oven to 350°F.
  2. Grease a 9×13-inch baking dish with butter.
  3. Place the cubed potatoes in a large pot and cover with salted water.
  4. Bring to a boil and cook for 15–20 minutes, or until the potatoes are very tender.
  5. Drain the potatoes well.
  6. Mash until smooth.

Make the Casserole

  1. Stir the melted butter and sour cream into the mashed potatoes until smooth and well combined.
  2. Add the beaten eggs, diced onion, salt, pepper, and garlic powder, if using.
  3. Mix thoroughly until evenly incorporated.
  4. Spread the potato mixture evenly into the prepared baking dish.
  5. Sprinkle shredded cheddar cheese over the top, if using.

Make Ahead or Bake Immediately

  • To make ahead, cover tightly and refrigerate for up to 24–48 hours.
  • To bake immediately, proceed with the baking instructions below.

Bake

  1. If refrigerated, remove the casserole from the refrigerator 20–30 minutes before baking, if possible.
  2. Cover tightly with foil and bake at 350°F for 30 minutes.
  3. Remove the foil and continue baking for 15–20 minutes, until heated through and lightly golden on top.
  4. Serve warm.

Jessica’s Notes

Best Served With

  • Roast turkey
  • Holiday ham
  • Prime rib
  • Roast chicken
  • Green bean casserole
  • Roasted vegetables
  • Cranberry sauce

Wine Pairings

  • Chardonnay complements the creamy potatoes with buttery notes and enough acidity to balance the richness.
  • Pinot Noir pairs well with savory onion flavors and roasted meats served alongside the casserole.
  • Sauvignon Blanc provides brightness and freshness that cuts through the sour cream and butter.
  • Cabernet Sauvignon works beautifully when served with steak, prime rib, or other hearty main dishes.
  • Sparkling wine adds acidity and a refreshing contrast to this rich, comforting side.

Prep Ahead

  • This casserole is ideal for holidays and entertaining because it can be assembled up to 48 hours ahead.
  • Prepare completely, cover tightly, and refrigerate until ready to bake.
  • Add an extra 10–15 minutes of baking time if going directly from the refrigerator to the oven.

Storage

Store leftovers in an airtight container in the refrigerator for up to 4 days.

Reheating

Reheat covered in a 350°F oven until warmed through, about 20–30 minutes. Add a small pat of butter or splash of milk before reheating if the potatoes seem dry.

Freezer-Friendly

Freeze baked or unbaked casserole for up to 2 months. Thaw overnight in the refrigerator before baking or reheating.

Variations

  • Add cooked bacon and green onions for loaded mashed potato casserole.
  • Stir in roasted garlic for deeper flavor.
  • Substitute cream cheese for part of the sour cream for an extra creamy texture.
  • Add Parmesan cheese to the topping for a golden, savory crust.
  • Mix in chopped fresh herbs such as chives, parsley, or thyme. 

Popular posts from this blog

Sourdough Honey Oat Wheat Sandwich Bread

Image
Prep Time: 45 minutes active (plus fermentation and overnight proof) Bake Time: 60–70 minutes Total Time: About 2½–3 days Yield: 2 loaves (or 1 loaf using the half-batch variation) Category: Bread ⸻ Notes After Making Add ⸻ Ingredients Starter Prep (Night Before – Day 1) Feed your sourdough starter the night before baking so it is active, bubbly, and ready to use. Glass jar reference weights: Jar + black lid: 470 g Jar only: 456 g Dough 2 cups (200 g) rolled oats 2 cups (480 g) hot water 114 g oil or melted butter 100 g honey (about 5 tablespoons) 300 g active sourdough starter 240-260 g room-temperature water 18 g (3 teaspoons) salt Choose ONE Flour Option Option 1 – Standard Flour Mix 500 g all-purpose flour 500 g whole wheat flour Option 2 – Bread Flour Substitute Blend 460 g all-purpose flour 450 g whole wheat flour 90 g vital wheat gluten Half Batch (Yield: 1 Loaf) Dough 1 cup (100 g) rolled oats 1 cup (240 g) hot water 57 g oil or melted butter 50 g...
Read more

Kitchen Sink Oatmeal Cookies

¾ cup (167 g) salted butter, softened ¾ cup (160–200 g) dark brown sugar, packed (use dark for richer flavor) ¼ cup (60 g) granulated sugar 1 large egg 1 tablespoon (15 ml) canola or neutral oil 1 tablespoon (15 ml) vanilla extract 1½ cups (190 g) all-purpose flour 1½ tablespoons (12 g) cornstarch 1 teaspoon baking soda ½ teaspoon salt 1 teaspoon ground cinnamon ¼ teaspoon freshly grated nutmeg ¼ teaspoon ground cardamom (or substitute ground ginger) 1½ cups (150 g) old-fashioned rolled oats ½ cup (90 g) semisweet chocolate chips ½ cup (90 g) butterscotch chips ⅓ cup (50 g) raisins ⅓ cup (45 g) chopped walnuts or pecans Preheat the oven to 350°F and line two baking sheets with parchment paper or silicone liners. In a large bowl, beat ¾ cup (167 g) salted butter with ¾ cup (dark brown sugar) and ¼ cup (granulated sugar) until light and fluffy, about 2 minutes. Add 1 large egg, 1 tablespoon of canola oil, and 1 tablespoon of vanilla extract, mixing until smooth and we...
Read more

Pizza Bowl

Image
  ½   cup   (60 g) all-purpose flour or 1/2 whole wheat flour  ¼   teaspoon   baking powder ⅛   teaspoon   baking soda ¼   teaspoon   salt ⅓   cup (75 g)   milk 2   tablespoons   olive oil 2   tablespoons   pizza sauce 2-3  tablespoons shredded mozzarella cheese 5 pepperonis or pre-cooked meat of choice ½   teaspoon   dried Italian herbs,  basil or oregano Mix the flour, baking powder, baking soda and salt together in a microwavable bowl. Add in the milk and oil then mix together, it’s ok if some lumps. Spoon on the  pizza sauce  and spread it around the surface of the batter. Sprinkle on the cheese, pepperoni, and dried herbs. Microwave for roughly 2 minutes or so, until it rises up and the toppings are bubbling. Ingredients (for ¾ cup flour version) • ¾ cup (90 g) all-purpose flour or half whole wheat flour • ⅓ teaspoon baking powder • ¼ teaspoon baking soda • ⅓ teaspoon salt ...
Read more