Loaded Mashed Potato Casserole (Make-Ahead Recipe) (2024)

Why Should You Try This Recipe?

Talk about a double-layered treat! This casserole with mashed potatoes has become a favorite side dish at dinner parties and holiday celebrations. I know your friends and family will go crazy for this one. Here’s why:

• It’s a two-for-one potato recipe! No longer do you have to choose between sweet or savory potatoes – this great recipe is the perfect way to have the best of both worlds!
• Easy to make ahead of the week you are going to serve. Simply make the recipe to completion, then pop it in the oven the day of serving to heat it back up!
• Simple enough to make as part of a celebratory weeknight dinner and festive enough to include as part of your holiday meal (i.e., Easter dinner, Thanksgiving meal or Christmas spread)
• Inspired by my Easy Mashed Sweet Potatoes and Sweet Potato Casserole recipes, this loaded mashed potato casserole is visually impressive too.

Ingredients

The ingredient list for this mashed potato recipe for dinner is super simple and not unlike what you would have put on your grocery list for traditional mashed potatoes.

Gather together sweet potatoes, Yukon gold potatoes, Kosher salt, milk, cream, butter, and black pepper. The totally optional, but totally craveable, crispy leek topping includes all-purpose flour, leeks, and avocado oil.

• Sweet potatoes: My favorite sweet potato variety is Garnet, which I find to be super bright orange and extra starchy. Jewel is another great option, as well as Beauregard, the most common type of sweet potato sold in grocery stores.
• Yukon gold potatoes: These provide an extra creamy texture and rich flavor. Russet or red potatoes (like it is in this red-skinned mashed potatoes recipe)
• Toppings to make it “loaded”: I used lightly fried leeks, crispy turkey bacon, and fresh herbs as a topping but they are optional and can be omitted if you like.

How to Make It?

Once I realized I could combine sweet potatoes and white potatoes into a baked mashed potato casserole masterpiece, my life was completely transformed. The crispy leeks at the very end add that extra bit of finesse (especially if you are serving it as a holiday side dish) and savory bite but they are optional.

1. Boil potatoes: Place sweet potatoes and Yukon gold potatoes in two separate saucepans (I used my 3-quart saucepan for cooking them). Cover each pot of potatoes with enough water to cover them. Season water generously with salt. Bring them to a boil and let them cook until they are fork-tender. Drain. Return potatoes to respective pans. Here is a helpful tutorial on How To Boil Potatoes, if you are new to cooking potatoes.

2. Mash potatoes: Pre heat oven to 400 °F. Whisk together the ¾ cup milk, ¾ cup heavy cream, and 4 oz. (1 stick) melted and cooled butter in a mixing bowl. Divide the mixture in between the saucepans. Using a potato masher or hand mixer, mash potatoes until smooth. Give it a taste and season with salt and pepper.

3. Layer potato casserole: Spread mashed sweet potatoes in an oval-shaped (or 9 x 11 inch rectangular) casserole dish. Using the back of a spoon or a spatula, smooth out the top into one even layer. Top with the mashed Yukon gold potatoes and spread it evenly to the edges, creating delicate divots and crevices.
4. Bake: Bake until golden, 20-25 minutes.

5. Fry leeks: Meanwhile, mix together the flour, leeks and a pinch of salt. Toss to coat. Heat the avocado oil in a medium saucepan over medium-high heat for 2 minutes. Add leeks into the oil and fry, turning occasionally, until crisp and golden around the edges. Transfer the crispy leeks onto a plate lined with a paper towel. Season the crispy leeks with additional salt and pepper.
6. Finish and serve: Sprinkle the leeks and bacon crumbles (if using) over the potato casserole. Serve immediately.

What to Make with Mashed Potatoes as a Side?

A few of my favorite main dishes with mashed potato casserole include:

• Dutch oven beef stew
• Turkey Meatloaf
• Whole roasted chicken
• Ina Garten’s pot roast
• Orange fennel chicken
• Cornish hens

FAQs

5 from 1 vote

For the mashed potatoes:

• ▢ 2 pounds 3-4 medium sweet potatoes, peeled and cut into small cubes
• ▢ 2 pounds 4-5 medium Yukon gold potatoes, peeled and cut into small cubes
• ▢ Kosher salt

For the milk & cream mixture:

• ▢ ¾ cup whole milk
• ▢ ¾ cup heavy cream
• ▢ 1 stick butter melted and cooled - 4oz.
• ▢ Freshly cracked black pepper

For the toppings (Optional)

• ▢ 2 tablespoons all purpose flour
• ▢ 1 leek white and pale green parts only, cut into ¼-inch rings, rinsed well and patted dry
• ▢ 2-3 tablespoons avocado oil
• ▢ 6 slices bacon or turkey bacon Cooked - (Omit for vegetarian version)

• Boil potatoes: Place sweet potatoes and Yukon gold potatoes in two separate saucepans. Cover each pot of potatoes by 1-inch of water. Salt them generously. Bring them to a boil and let them cook until they are fork tender. Drain. Return potatoes to respective pans.

• Mash potatoes: Preheat the oven to 425 °F. Whisk together the milk, heavy cream, and butter in a mixing bowl. Divide the mixture in between the saucepans. Using a potato masher or hand blender, mash potatoes until smooth. Season with salt and pepper.

• Lightly spray a casserole dish with cooking spray. I used an oval-shaped (or 9 x 11 inch rectangular) casserole dish.

• Layer potatoes: Spread mashed sweet potatoes in the prepared casserole dish. Using the back of a spoon or a spatula, smooth out the top into one even layer. Top with the mashed Yukon gold potatoes and spread it evenly to the edges, creating delicate divots and crevices.

• Bake: Bake until golden, 20-25 minutes.

• Fry leeks: Meanwhile, mix together the flour, leeks and a pinch of salt. Toss to coat. Heat the avocado oil in a medium saucepan over medium-high heat for 2 minutes. Add leeks into the oil and fry, turning occasionally, until crisp and golden around the edges. Transfer the crispy leeks onto a plate lined with a paper towel.

• Finish and serve: Season the crispy leeks with additional salt and pepper. Sprinkle them over the potato casserole. Serve immediately.

• Don’t overmix the potatoes, or they will have a gummy texture.
• Bring all ingredients to room temperature. Room temperature milk, cream, and slightly warm melted butter blend better with the warm potatoes.
• Create deep pockets of divots and peaks on the top layer of the potato casserole just before baking. This ensures a golden crust, with deep, dark, caramelized bits.
• Add toppings after baking. No matter if you stick with the crispy leeks, or go fully loaded with bacon and chives, add after baking to keep the integrity of the toppings. The exception to this rule is cheese - add that while baking for a delectable cheesy finish.
  
• To make ahead - Boil, mash and assemble the two layers, then wrap the entire casserole dish in plastic wrap, then in foil. Bring to room temperature and store in the fridge for up to 3 days or in the freezer for up to 1 month. Thaw overnight in the fridge, if frozen. Reheat in a 350 degree F oven until the center is warmed through.Crispy Leeks: Prepare on the day you are going to serve while the casserole is reheating in the oven.