Cheesy Potato and Spinach Casserole
Tender potatoes and spinach baked in a creamy garlic sauce with cheddar and parmesan until golden and bubbly. An easy make-ahead side for Thanksgiving and Christmas.
This cheesy potato casserole is a cozy holiday side that feeds a crowd. Chunks of tender potato and spinach are coated in a creamy garlic sauce, then baked with cheddar and parmesan until golden on top.
Parboiling the potatoes first means they cook evenly and the casserole is ready in about 45 minutes in the oven.
Assemble it the day before and bake it while the turkey rests.
Why You’ll Love This Recipe
- Creamy and cheesy
- Make it a day ahead
- Sneaks in some greens
- Kid-friendly side
Ingredient Notes
Potatoes: Yukon gold potatoes hold their shape and have a buttery flavor. Russets work but are softer.
Spinach: Use frozen chopped spinach, thawed and squeezed very dry, or 6 cups of fresh spinach wilted in a pan.
See the recipe card below for full measurements.
How to Make Cheesy Potato and Spinach Casserole
Parboil the potatoes
Heat the oven to 375°F (190°C) and butter a 9 x 13 inch dish. Boil the potatoes in salted water for 7 to 8 minutes, just until a fork goes in with some resistance. Drain well.
Make the sauce
Melt the butter in a saucepan over medium heat. Add the garlic for 30 seconds, then whisk in the flour for 1 minute. Slowly whisk in the milk and simmer 3 to 4 minutes until thick.
Season
Off the heat, stir in the sour cream, salt, pepper, nutmeg, 1 cup of cheddar and half the parmesan until melted.
Combine
Gently fold the potatoes and spinach into the sauce and spread in the dish.
Top and bake
Sprinkle with the remaining cheddar and parmesan. Bake 30 to 35 minutes until bubbly and golden on top.
Rest
Rest 10 minutes before serving so the sauce thickens.
Tips for the Best Results
- Squeeze the spinach completely dry so the casserole is not watery.
- Do not overboil the potatoes; they finish in the oven.
- Broil for 2 minutes at the end for a crispier top.
- Add 1/2 cup sliced green onions for extra flavor.
Common Mistakes to Avoid
| Mistake | How to fix it |
|---|---|
| Watery casserole | Squeeze the spinach dry and drain the potatoes well. |
| Mushy potatoes | Parboil only until just tender. |
| Lumpy sauce | Add the milk slowly while whisking. |
Substitutions
- Spinach: Chopped broccoli or kale.
- Sour cream: Plain Greek yogurt.
- Cheddar: Gruyere-style or Monterey Jack cheese.
What to Serve With It
- Easy roast turkey
- Garlic herb roast beef
- Homemade cranberry sauce
- Honey roasted carrots
Storage and Reheating
Fridge: Assemble up to 1 day ahead, or keep baked leftovers for 4 days.
Freezer: Freeze baked casserole for up to 2 months.
Reheat: Cover and warm at 350°F (175°C) for 20 to 25 minutes. Add 10 minutes if baking straight from the fridge.
Tools That Make This Easier
- 9 x 13 inch baking dishThe right size for 8 servings.Check price on Amazon
- Potato ricerAlso squeezes spinach dry in seconds.Check price on Amazon
- Box graterFreshly grated cheese melts best.Check price on Amazon
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Cheesy Potato and Spinach Casserole
Tender potatoes and spinach baked in a creamy garlic sauce with cheddar and parmesan until golden and bubbly. An easy make-ahead side for Thanksgiving and Christmas.
Ingredients
Casserole
Instructions
- Heat the oven to 375°F (190°C) and butter a 9 x 13 inch dish. Boil the potatoes in salted water for 7 to 8 minutes, just until a fork goes in with some resistance. Drain well.
- Melt the butter in a saucepan over medium heat. Add the garlic for 30 seconds, then whisk in the flour for 1 minute. Slowly whisk in the milk and simmer 3 to 4 minutes until thick.
- Off the heat, stir in the sour cream, salt, pepper, nutmeg, 1 cup of cheddar and half the parmesan until melted.
- Gently fold the potatoes and spinach into the sauce and spread in the dish.
- Sprinkle with the remaining cheddar and parmesan. Bake 30 to 35 minutes until bubbly and golden on top.
- Rest 10 minutes before serving so the sauce thickens.
Nutrition (per serving)
- Calories
- 330 kcal
- Protein
- 13 g
- Carbohydrates
- 33 g
- Total Fat
- 17 g
- Saturated Fat
- 10 g
- Fiber
- 4 g
- Sugar
- 5 g
- Sodium
- 640 mg
Nutrition is an estimate per serving without optional sauces, calculated from standard USDA values. It will vary with brands and portion sizes.
Frequently Asked Questions
Can I make potato casserole ahead?
Yes. Assemble it up to 1 day ahead, cover and refrigerate. Add about 10 minutes to the baking time.
Do I need to boil the potatoes first?
Yes, briefly. Parboiling for 7 to 8 minutes makes sure the potatoes cook evenly in the oven.
Can I use fresh spinach?
Yes. Wilt 6 cups of fresh spinach in a pan, cool and squeeze out the water before adding.
What potatoes are best for casserole?
Yukon gold potatoes hold their shape and taste buttery. Russets work but get softer.
