This Garlic Mashed Potato Casserole is the ultimate comfort food! Creamy mashed potatoes meet a tasty garlic twist, all baked to golden perfection. Yum!
It’s so easy to make, you’ll wonder why you haven’t tried it sooner! I like to add a sprinkle of cheese on top for that extra cheesy goodness. Trust me, everyone will ask for seconds! 😄
Key Ingredients & Substitutions
Russet Potatoes: These are my go-to for a fluffy texture in mashed potatoes. If you prefer, you can use Yukon Gold potatoes for a creamier texture. Just make sure they’re fully cooked before mashing!
Garlic: Fresh garlic gives a great flavor boost! If you’re short on time, you can use garlic powder, about 1 teaspoon for every clove, but fresh is always best. You can also roast garlic for a sweeter flavor.
Sour Cream: I love sour cream for the tangy flavor and creaminess it adds. Greek yogurt is a healthier substitute if you’re looking for something lighter, just make sure to choose plain.
Cheddar Cheese: Cheddar is cheesy and adds great flavor! If you want to experiment, you could use Monterey Jack or a mix of cheeses for different taste profiles. I sometimes mix in some cream cheese for extra creaminess.
How Can I Get the Perfect Texture for My Mashed Potatoes?
Getting the right texture is crucial for mashed potatoes. Follow these tips for fluffy results:
- Use a potato masher or ricer for smoothness; a fork might leave lumps.
- Don’t over-mash, or you’ll get gummy potatoes!
- Warm your milk before adding to help everything blend better.
- Make sure butter is melted and garlic is sautéed to avoid any raw taste.
Give these techniques a try, and you’ll have a delicious garlic mashed potato casserole that everyone will love!

Garlic Mashed Potato Casserole
Ingredients You’ll Need:
For the Mashed Potatoes:
- 4 large russet potatoes, peeled and chopped
- 4 cloves garlic, minced
- 1/2 cup unsalted butter, melted
- 1 cup sour cream
- 1/2 cup milk (whole or 2%)
- 1 1/2 cups shredded cheddar cheese, divided
- Salt and pepper to taste
For the Garnish:
- 1/4 cup green onions, chopped (for garnish)
- 1/4 cup fried onions or crispy shallots (for topping, optional)
How Much Time Will You Need?
This Garlic Mashed Potato Casserole will take about 15 minutes to prepare and around 30 minutes to bake in the oven. You’ll have a delicious, cheesy casserole ready in under an hour!
Step-by-Step Instructions:
1. Preheat the Oven:
Start by preheating your oven to 350°F (175°C). This way, it’ll be hot and ready for your casserole when you’re done prepping!
2. Cook the Potatoes:
Place the chopped russet potatoes into a large pot and cover them with cold water. Bring the water to a boil over high heat. Once boiling, reduce the heat to medium and let the potatoes cook until they’re very tender, which should take about 15-20 minutes.
3. Sauté the Garlic:
While the potatoes are cooking, melt the butter in a small pan over medium heat. Add the minced garlic and sauté for about 1-2 minutes, or until fragrant and lightly golden. Be careful not to burn the garlic! Once done, remove from heat.
4. Prepare the Mashed Potatoes:
Once the potatoes are cooked, drain them thoroughly and transfer them to a large mixing bowl. Mash the potatoes until smooth. Then, stir in the sautéed garlic butter, sour cream, milk, and 1 cup of shredded cheddar cheese. Add salt and pepper to taste and mix until everything is well combined.
5. Assemble the Casserole:
Transfer the creamy mashed potato mixture into a greased casserole dish, spreading it evenly across the dish. Sprinkle the remaining 1/2 cup of shredded cheddar cheese on top for that delicious cheesy crust.
6. Bake:
Place the casserole in the preheated oven and bake for about 25-30 minutes, or until the cheese is melted and the top is golden. If you like it extra crispy, feel free to broil it for a couple of minutes at the end!
7. Add Toppings:
If you’re using fried onions or crispy shallots, sprinkle them on top during the last 5 minutes of baking so they can get nice and crunchy.
8. Serve and Enjoy!
Remove the casserole from the oven and garnish with chopped green onions before serving. Everyone will love this creamy, garlicky, cheesy delight!
Enjoy every mouthful of your Garlic Mashed Potato Casserole! 🎉✨
Can I Use Different Types of Potatoes?
Yes! While russet potatoes are great for a fluffy texture, you can use Yukon Gold potatoes for a creamier finish. Just make sure to cook them until very tender for the best results.
Can I Make This Ahead of Time?
Absolutely! You can prepare the mashed potatoes and assemble the casserole a day in advance. Just cover it tightly and refrigerate. When you’re ready to bake, you may need to add a few extra minutes to the cooking time.
What Can I Substitute for Sour Cream?
If you’re looking for a healthier option, plain Greek yogurt works wonderfully! You could also use cream cheese for a richer flavor. Just mix it well to incorporate.
How Do I Store Leftovers?
Store any leftovers in an airtight container in the fridge for up to 3 days. To reheat, warm it gently in the oven at 350°F (175°C) until heated through, or use the microwave, adding a splash of milk if it seems dry.



