Creamy garlic herb mashed potatoes casserole in a red dish on a blue and white towel.
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2.37 from 11 votes

Garlic Mashed Potatoes Casserole

This scrumptious Make-Ahead Garlic Mashed Potatoes Casserole is easy to make for a crowd or just for those busy weeknights when you want something special. They reheat wonderfully and are freezer friendly too! (yes!)
Prep Time30 mins
Cook Time40 mins
Total Time1 hr 10 mins
Course: Side Dish
Cuisine: American
Keyword: Garlic Mashed Potatoes Casserole
Servings: 2 casseroles
Calories: 1320kcal
Author: Brenda Thompson

Ingredients

Garlic & Herb Cheese Spread

  • 16 ounces light cream cheese softened
  • ½ cup light sour cream
  • ¼ cup Parmesan cheese grated
  • 2 cloves garlic minced
  • 2 teaspoons dried parsley
  • 1 teaspoon dried chives
  • 1 teaspoon dried dill
  • ½ teaspoon dried basil
  • ½ teaspoon black pepper
  • ¼ teaspoon dried thyme

For Garlic Mashed Potatoes Casserole:

  • 5 pounds Yukon Gold potatoes
  • 2 cups garlic herb cheese spread recipe above
  • cup low-fat milk

Instructions

For Cream Cheese Mixture

  • In large bowl, use a mixer to combine all ingredients until smooth.
  • Portion and freeze or follow assembly instructions below for casserole.

For Potatoes

  • Peel potatoes and cut into 2-inch chunks.

Potatoes: Stove-top Method

  • Place cut potatoes in a 5 to 6 quart pan.
  • Add water to cover, bring to a boil over high heat.
  • Reduce heat to low.
  • Simmer until the potatoes are very tender about 20-25 minutes.

Potatoes: Pressure Cooker Method

  • In a 6-quart pressure cooker, place trivet in bottom.
  • Add one cup of water and then add cut potatoes.
  • Set time to 5 minutes.
  • Once potatoes are done, use quick release method to release steam.

With Cooked Potatoes, follow from here

  • Drain and return potatoes to the pan.
  • Mash potatoes with a potato masher until light and dry and smooth.
  • Stir in herb cheese mixture and milk until smooth.
  • Add salt and pepper to taste.
  • Cool potatoes casserole to room temperature.
  • Divide potatoes into tins and cover with foil. Or follow one of the methods described in the blog post.
  • Label with recipe name and date. Freeze.

To Prepare Potatoes Casserole

  • Thaw in refrigerator overnight. Or these may be baked from frozen.
  • Preheat oven to 375F degrees.
  • Bake thawed potatoes casserole for 40 minutes or 90 minutes if frozen.
  • Remove foil from casserole dish then bake and additional 5-10 minutes until golden on top.

Notes

Potatoes may look watery before freezing, but the water will be absorbed as they bake. You can substitute russet potatoes if you prefer, but I think Yukon Gold potatoes yield a more creamy, flavorful potato casserole.

How to Make Ahead Garlic Mashed Potatoes

As I’ve mentioned in the blog post, this casserole CAN be frozen!
There are a few extra things you can prep ahead of time as well. I like to cook the mashed potatoes in my pressure cooker. They are SO easy and it’s a lot quicker.  You can also boil them in a large pot.
Once the potatoes are cooked, go ahead and mash them then store in the refrigerator until you are ready to assemble the casserole. You can do this up to three days in advance.
Additionally, the cream cheese mixture can also be made up to three days in advance and stored in the refrigerator also until ready to assemble.
Once you’ve assembled the casserole mixture (use a big bowl!) divide it up into the serving size that makes sense for you. As mentioned, the original recipe will make two 8-serving casseroles. If you will be baking right away, follow the instructions on the recipe card.
If you will be freezing one (or more) for later, keep reading.

How To Freeze Garlic Mashed Potatoes Casserole

Choose freezer safe containers. I will sometimes purchase disposable foil containers with lids at the dollar store. They also have them at the grocery store or online.
Other times I will line an 8x8 casserole dish of mine with foil then put my casserole mixture in. I cover it with more foil then label with name and date then put in the freezer until it’s solid. This will take about 24 hours.
After that, I will pop it out of the dish, flip it over and wrap the top layer of foil around the edges. It’s kind of like a giant popsicle of mashed potatoes! Since it was labeled before putting it in the freezer, it is good to go back in the freezer.
When I’m ready to make it, I simply place it back into the baking dish and let it thaw in the refrigerator until ready to bake. You can also cook it from frozen (see recipe card for instructions).
I’ve also frozen the casserole in a zip top bag—disposable or reusable like these.  This is a bit trickier because sometimes it’s hard to get all of it out of the bag, but it works well enough that it’s a fine option.
If you'd like to make smaller portions, consider freezing it these two cup Souper Cubes silicone molds or the one-cup style. I love my Souper Cubes and use them all the time!
You’ll just let it thaw in the refrigerator then empty the contents into a baking dish and bake according to the recipe instructions.

Nutrition

Serving: 0.75cup | Calories: 1320kcal | Carbohydrates: 175g | Protein: 59g | Fat: 47g | Saturated Fat: 28g | Cholesterol: 158mg | Sodium: 1489mg | Potassium: 5660mg | Fiber: 29g | Sugar: 21g | Vitamin A: 3540IU | Vitamin C: 147mg | Calcium: 1129mg | Iron: 38mg