Caramelized Onion and Roasted Garlic Buttermilk Mashed Potatoes with Parmesan are the picture perfect example of just how powerfully marvelous mashed potatoes can be! Level up any meal with these delicious creamy mashed potatoes as a side.
One of my brothers loves mashed potatoes and gravy more than any other human on planet Earth.
He’s an expert at constructing a mashed potato moat, inside which the most substantial portion of gravy assertively resides. He then eats the mashed potatoes + moat in such a way that doesn’t break the dam, leaving the other food on his plate completely undisturbed.
Look, I’m going to give it to you straight.
Unless mashed potatoes are sinfully creamy, cheesy and loaded to the brim with onion and garlic, I want zero part of them. Add in some bacon and butter for extra credit, and I’m full-tilt committed.
Leave out those mega rich flavors, and I’m not touching it with a 10-foot fork.
Don’t get me started on gravy.
Now that we know my preferences, I can safely say, these Caramelized Onion and Roasted Garlic Buttermilk Mashed Potatoes are the best mashed potatoes I’ve ever made in my life.
Unless of course, you count mashed sweet potatoes, in which case my Maple Bourbon Mashed Sweet Potatoes pose an incredibly fierce competition.
In honor of my picky self and my potato-obsessed brother, I hereby give the world a mashed potato every human will not just tolerate, but enjoy. Nay, love.
What makes these mashed potatoes so lusciously enticing?
We have TWO full onions that get caramelized to perfection in addition to an entire bulb of roasted garlic, with a very generous portion of buttermilk and a record-breaking amount of parmesan cheese.
I leave the butter optional, but you know you want it, so you might as well go get iiiiit.
Seriously, these taters are slutty.
The opposite of bland.
Before we go any deeper, let’s give the ingredients a once over.
Ingredients for The BEST Mashed Potatoes on the Planet:
Potatoes (I recommend russet or yukon gold, but any will work)
Buttermilk
Parmesan Cheese
Yellow Onions
Garlic
Sea Salt
If you don’t do fresh dairy (I very rarely do), you can replace the buttermilk with full-fat canned coconut milk plus 2 to 3 tablespoons of cider vinegar or rice vinegar. This dairy-free formula will provide that creamy tang.
The combination of the caramelized onion, roasted garlic, and oh so tangy buttermilk with the smooth nutty parmesan is enough to blow my mind socket.
But don’t take my word for it! Take them for a test drive!
How to Make Caramelized Onion and Roasted Garlic Buttermilk Mashed Potatoes:
The caramelized onion and roasted garlic take a fair amount of time, so start the cooking process by tackling the caramelized onion first. As the onion is caramelizing, you can roast the garlic and cook the potatoes. By the time the onion has finished caramelizing, you should be ready to compile the mashed potatoes.
Caramelize the Onion: Add the avocado oil to a large non-stick skillet and heat to medium-high. Add the chopped onions and sprinkle liberally with sea salt. Cover the skillet and cook, stirring occasionally, until the onions leach a lot of their liquid, turn translucent and have softened.
Remove the cover from the skillet and reduce the heat to medium or medium-low. Continue cooking, stirring occasionally, until the onions are brown and caramelized, about 50 to 60 minutes total.
Roast the Garlic: Cut the top off of the bulb of garlic and place it on a sheet of foil. Drizzle with avocado oil then wrap the bulb in the foil so that it’s fully covered. Roast at 400 degrees Fahrenheit for 35 to 45 minutes, or until the garlic cloves are deeply golden-brown. Remove garlic from the oven and set aside until ready to use.
Once the garlic is cool enough to handle, turn the bulb upside down over a cutting board and squeeze it to release all of the cloves. The cloves should squeeze out relatively easily. Chop up the cloves into finer pieces.
Cook the Potatoes: Bring a pot of water to a boil on the stove top. Peel and chop the potatoes into 3-inch chunks (or roughly equal sized chunks) and transfer to the boiling water. Cook at a continuous boil until the potatoes are very soft when poked with a fork, about 15 to 20 minutes. Drain the potatoes into a colander, then transfer them back into the same pot you used for boiling.
Make the Mash: Add the buttermilk, parmesan cheese, butter, and sea salt to the pot with the hot cooked potatoes and mash using a potato masher until the potatoes reach your desired consistency. Pro tip: if you don’t own a potato masher, you can use the back of a sturdy plastic measuring cup or the bottom of a wine bottle. Taste the mashed potatoes for flavor and add more sea salt, parmesan cheese, and/or butter to taste.
Add the caramelized onions and chopped roasted garlic to the pot and stir well to combine.
Serve with your main dish and enjoy!
While this recipe requires several parts, each part is incredibly straightforward and simple. If you can’t set aside a full hour to make the mashed potatoes, you can break the recipe into pieces.
Prep Ahead:
Want to make this recipe in parts to cut the prep time into chunks? This is a great recipe for that!
Make the caramelized onions or roast the garlic up to 5 days ahead of time.
Cook the potatoes up to 4 days ahead of time and store them in a container in the refrigerator until ready to use. Mash the potatoes on the stove top with the ingredients over medium heat when you’re ready to bring the whole recipe together.
Recipe Adaptations:
- As previously mentioned, you can replace the buttermilk with full-fat canned coconut milk plus 2 to 3 tablespoons of cider vinegar or rice vinegar (an ideal option that is fresh dairy-free for those who can tolerate cheese but not fresh dairy like milk, cream, or buttermilk).
- Replace the buttermilk with half & half or regular milk if you prefer, but just know you’ll be missing out on that tangy deliciousness.
- Replace the parmesan cheese with any cheese you love. Asiago, cheddar, gruyere and gouda are all exceptional options.
- Add any seasonings or black pepper to your personal taste.
- Bacon? Do it! Cook up 4 to 6 stips of bacon, give them a chop and toss them in.
- Chives? Why not! Feel free to add up to ¼ cup of chopped chives.
- Use any type of potato but note that your buttermilk needs will be lower for all sweet potato varieties as they are inherently moister than your average russet potato. Adjust as needed.
Make these mashed potatoes any time the craving strikes, for any date night meal, for serving guests, and for holiday entertaining.
It is guaranteed to level up any dinner, so I 1,000 out of 10 recommend this for any special gathering. It’ll be a central part of my family’s Thanksgiving feast!
More Delicious Potato Side Dishes:
- Healthy Sweet Potato Casserole
- Mediterranean Scalloped Potatoes
- Cheesy Mashed Sweet Potato Casserole
- Herbed Coconut Milk Potatoes Au Gratin
- Sweet Potato Hash with Bacon and Spinach
I hope you’re as over the moon about this mash as I am!
If you make this luscious creamy Caramelized Onion and Roasted Garlic Buttermilk Mashed Potatoes recipe, feel free to share a photo on Instagram and tag me @The.Roasted.Root!
Ingredients
- 3 lbs yukon gold or russet potatoes, peeled and chopped into chunks*
- 2 Tbsp avocado oil
- 2 large yellow onions, finely chopped
- 1 bulb garlic
- 1 1/2 cups buttermilk**
- 2 cups parmesan cheese, or to taste
- 3 Tbsp unsalted butter, optional
- 1 tsp sea salt, to taste
Instructions
Caramelize the Onion:
- Add the avocado oil to a large non-stick skillet and heat to medium-high. Add the chopped onions and sprinkle liberally with sea salt. Cover the skillet and cook, stirring occasionally, until the onions leach a lot of their liquid, turn translucent and have softened.
- Remove the cover from the skillet and reduce the heat to medium or medium-low. Continue cooking, stirring occasionally, until the onions are brown and caramelized, about 50 to 60 minutes total.
Roast the Garlic:
- Cut the top off of the bulb of garlic and place it on a sheet of foil. Drizzle with avocado oil then wrap the bulb in the foil so that it’s fully covered. Roast at 400 degrees Fahrenheit for 35 to 45 minutes, or until the garlic cloves are deeply golden-brown. Remove garlic from the oven and set aside until ready to use.
- Once the garlic is cool enough to handle, turn the bulb upside down over a cutting board and squeeze it to release all of the cloves. The cloves should squeeze out relatively easily. Chop up the cloves into finer pieces.
Cook the Potatoes:
- Bring a pot of water to a boil on the stove top. Peel and chop the potatoes into 3-inch chunks (or roughly equal sized chunks) and transfer to the boiling water. Cook at a continuous boil until the potatoes are very soft when poked with a fork, about 15 to 20 minutes. Drain the potatoes into a colander, then transfer them back into the same pot you used for boiling.
Make the Mash:
- Add the buttermilk, parmesan cheese, butter, and sea salt to the pot with the hot cooked potatoes and mash using a potato masher until the potatoes reach your desired consistency. Taste the mashed potatoes for flavor and add more sea salt, parmesan cheese, and/or butter to taste.
- Add the caramelized onions and chopped roasted garlic to the pot and stir well to combine.
- Serve with your main dish and enjoy!
Notes
Nutrition
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