Caramelized Onion Mashed Potatoes (Vegan)
Recipe Highlights
These creamy mashed potatoes with sweet caramelized onions are a step up from plain mash without adding complexity. The onions bring a rich sweetness that pairs beautifully with the buttery potatoes.
The key is not holding back on the vegan butter and cream. Mashed potatoes are an indulgent side, so lean into it. The caramelized onions take 25-35 minutes, but they’re mostly hands-off.
Perfect for holiday meals or anytime you want a side dish that feels a bit more special.
Ingredients
Step by Step
The Caramelized Onions Are Worth the Time
Getting the onions properly caramelized makes all the difference. You want them deep golden brown and jammy, not just softened.
A heavy-bottomed pan, like cast iron, gives you even heat distribution, which prevents burning while allowing proper caramelization. The onions will go through stages—first releasing liquid, then turning golden, and finally reaching that deep caramel color.
If they start to stick or you hear sizzling, add a splash of water or stock to deglaze the pan and scrape up the browned bits. That’s flavor you don’t want to lose.
The longer you cook them (within reason), the sweeter and more concentrated they become. I usually take them to a deep mahogany color, but you can stop earlier if you prefer a milder flavor.
Make-Ahead Tips
The caramelized onions can be made a few days in advance. Store them in an airtight container in the fridge and reheat gently before incorporating them into the mash.
For the mashed potatoes themselves, you can prepare them a few hours ahead and keep them warm in a slow cooker on low, or reheat gently on the stovetop with a splash of extra plant milk to restore the creamy texture.
TIP: Use the vegan butter, cream, and milk that you like the taste of, as they will come through in the final dish.
Serving Ideas
For holiday meals:
- Serve alongside Vegan Lentil Loaf with steamed greens for a classic holiday spread
- Pair with Vegan Cabbage Rolls or Vegan Stuffed Peppers for a comforting feast
For everyday meals:
- Serve with Rich Vegan Pot Pie with TVP for a cozy, warming dinner
- Pair with Dal Makhani for a flavorful weeknight meal
- Add as a side to Chargrilled Capsicums and crusty bread
- Serve with Turkish Stewed Green Beans for a Mediterranean-inspired spread
- Pair with Eggplant Patties for a hearty dinner
Caramelized Onion Mashed Potatoes (Vegan)
- Prep Time: 15 minutes
- Cook Time: 40 minutes
- Total Time: 55 minutes
- Yield: 6-8 as a side
Description
Creamy vegan mashed potatoes rippled with sweet caramelized onions. Perfect holiday side that’s make-ahead friendly. Rich, indulgent, and pairs with any main.
Ingredients
Equipment:
- Measuring equipment (cup, teaspoon/tablespoon or scales)
- Knife
- Potato peeler
- Large skillet
- Wooden spoon
- Medium pot
- Potato masher
- Spoon
For the caramelized onions:
- 2 tablespoons olive oil
- 1 tablespoon vegan butter
- 3–4 onions (about 1.7 pounds / 800g), thinly sliced
- 1 teaspoon salt
- 1–2 teaspoons cane sugar (optional)
- 1 tablespoon balsamic vinegar (optional)
- ¼ cup / 60ml water or vegetable stock (for deglazing)
- Fresh thyme leaves* (optional)
- Ground black pepper, to taste
For the mashed potatoes:
- 3.3 pounds / 1.5kg starchy potatoes,* peeled and cut into chunks
- ⅔ cup / 145ml plant cream* (Country Crock, Silk, Flora, or Oatly creams work)
- ½ cup / 105g vegan butter
- ¼ cup / 60ml unsweetened neutral plant milk (I used unsweetened soy)
- 2 garlic cloves, minced
- Salt, to taste
- Ground black pepper, to taste
Instructions
Make the caramelized onions (start these first):
- Heat oil and butter: Heat the oil (2 tablespoons) and butter (1 tablespoon) in a large, heavy-bottomed pan/skillet over medium heat.
- Add onions and salt: Add the sliced onions and salt (1 teaspoon). Stir to coat everything evenly.
- Cook slowly: Cook, stirring occasionally, for 30-35 minutes. The onions will first release their liquid, then slowly turn golden, and finally, a deep caramel brown. Adjust heat as needed – you want them to caramelize, not burn. Move onto the mash during this step, just keep an eye on them.
- Deglaze if needed: If the onions start to stick or the onions are burning, add a splash of water or stock to deglaze the pan and scrape up the browned bits.
- Finish and season: Once deeply golden, add the sugar (1-2 teaspoons) and balsamic vinegar (1 tablespoon), if using (this helps with the final caramelization and adds a sharpness to the onions), cook for another 2-3 minutes, then season with pepper and fresh thyme if using. Taste and adjust seasoning if necessary. Set aside.
Make the mashed potatoes:
- Boil potatoes: While the onions are cooking, place potatoes in a medium pot of cold salted water. Bring to a boil with the lid on, and then remove and cook for 15-20 minutes until very tender when pierced with a fork.
- Drain and steam dry: Drain well and return to the pot. Let them steam dry for a minute.
- Mash with dairy-free ingredients: Mash the potatoes until smooth (or put through a potato ricer if you have one). Add the plant cream (⅔ cup), vegan butter (½ cup), soy milk (¼ cup), and 2 cloves of minced garlic. Continue mashing until creamy and fluffy. Season generously with salt and pepper to taste. This will depend on the butter and cream you use.
To serve:
- Layer with onions: Mix half of the caramelized onions through the mash. Transfer the mashed potatoes to a serving dish. Top with the rest of the onions (you can be very generous here, or pull back – you might have some left over), spreading them over the surface.
- Garnish: Drizzle with a little extra olive oil, and scatter with fresh herbs, if desired.
Notes
Herb variations: Add chopped fresh chives, parsley, sage, or rosemary to the mashed potatoes for a different flavor profile.
Potato varieties: For the fluffiest, creamiest mash, use starchy potatoes. In Australia, use Desiree or Sebago. In the US, Russet or Yukon Gold work perfectly. In the UK, opt for Maris Piper or King Edward. Avoid waxy potatoes, such as Charlotte or Anya, as they’ll create a gluey texture.
Cream substitute: You can use full-fat coconut milk instead of plant cream. The texture and flavor will be slightly different but still rich and creamy.
