Leftover Mashed Potato Cakes Aioli

If your fridge is greeting you with a bowl of mashed potatoes after a big holiday meal, do not let them languish. These leftover mashed potato cakes with garlic aioli take something humble and turn it into a dish with crispy golden edges and a fluffy, savory center. Fresh chives and easy homemade aioli make the whole thing taste like it was meant to be part of the original feast.

When I first made these, everyone circled back for seconds—now I make extra mashed potatoes on purpose just for this recipe

Ingredients

• Leftover mashed potatoes: chilled for easier shaping and best crisp factor
• All-purpose flour: gives the cakes structure so they hold together
• Chives or green onions: for fresh flavor and a pop of color, use whichever you have handy or both
• Garlic powder: layers in a savory warmth and is easier to evenly distribute than fresh garlic
• Egg: lightly beaten, works as the binder that brings everything together
• Olive oil or butter: for frying, choose butter for richness or olive oil for a lighter finish
• Mayonnaise: the creamy base of the aioli, choose a good-quality real mayo for best flavor
• Fresh garlic: minced for bright sharpness in the aioli, local or farmers market garlic is especially fragrant
• Fresh lemon juice: adds zing and livens up the mayo, use freshly squeezed for best results
• Salt and pepper: to finish and balance both the aioli and the cakes

Step-by-Step Instructions

Make the Potato Cake Mixture:

Combine the chilled mashed potatoes with flour, chives or green onions, garlic powder, and the beaten egg in a medium bowl. Mix until just combined without overworking—this keeps the cakes tender.

Shape the Patties:

Scoop out the mixture and shape it gently into eight to ten cakes about half an inch thick. Handle delicately so they do not get tough.

Fry the Cakes:

Heat olive oil or butter in a large skillet over medium heat. Once hot, arrange the cakes without crowding. Cook each side for three to four minutes until they are deeply golden and the exterior is crisp. Adjust heat as needed so they brown evenly without burning.

Make the Garlic Aioli:

While the cakes cook, whisk together mayonnaise, minced garlic, and lemon juice in a small bowl. Season with salt and pepper to taste. The aioli should taste bright and garlicky but not overwhelming.

Serve:

Plate the crisp potato cakes warm and add a dollop of the garlic aioli on top. Serve right away for the best contrast of crispy exterior and creamy dip.

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I always look forward to the fresh chives in this recipe. Their little oniony pop just whispers old-fashioned comfort and making these cakes the morning after Thanksgiving is one of my family's favorite rituals

Storage Tips

If you have leftovers, let the cakes cool fully before storing. Place in an airtight container with parchment between them to prevent sticking. They will keep well in the refrigerator for up to three days. Reheat them in a skillet over medium heat so they re-crisp outside rather than microwaving

Ingredient Substitutions

No chives or green onions: Try parsley or dill
Gluten-free desired: Use a one-to-one gluten-free flour blend
Mayo not your thing: You can make the aioli with sour cream or Greek yogurt for a tangy, lighter twist

Serving Suggestions

Serve these with a tangle of arugula salad and a fried egg for a brunch plate or next to roasted root vegetables for a cozy supper. They also work great as a side for roast chicken or alongside a big winter soup

A Little History

Potato cakes in some form show up in many cultures as a thrifty way to use up leftovers. Whether you call them boxty, bubble and squeak, or simply potato patties, they are all about stretching the bounty of a big meal and making something satisfying from what is left behind

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Common Questions

→ How do I prevent potato cakes from falling apart while frying?

Ensure the mashed potatoes are chilled and work in the flour and egg thoroughly to help bind the cakes. Handle gently when flipping.

→ Can I substitute chives with green onions?

Yes, finely chopped green onions work well and add a mild, fresh flavor to the potato cakes.

→ Is it possible to bake instead of fry the potato cakes?

Yes, you can bake them at 400°F (200°C) for 15-20 minutes on a lined baking sheet, flipping halfway through for even browning.

→ What can I use instead of mayonnaise for the aioli?

Greek yogurt or sour cream are great substitutes if you want a lighter or tangier version of the aioli.

→ How long can I store leftover potato cakes?

Refrigerate the cakes in an airtight container for up to 3 days. Reheat in a skillet or oven to restore crispiness.