Leftover mashed potatoes deserve better than microwaved mediocrity. These potato cakes turn that mash into something worth planning for: schmaltz-fried patties with shallot and green onion. Schmaltz brings depth, garlic confit (already in the mash) brings background richness, and the sriracha mayo bridges heat and acid.
Snapshot
- Implements: skillet; slotted spoon; mixing bowl; small bowl
- Stove setting: medium heat for shallot infusion and potato cake frying (about 10–12 minutes total frying time)
- Batch size: 3–4 servings
- Notes: Uses leftover mash from Ultra-Concentrated Baked Potato Mashed Potatoes with garlic confit already mixed in.
Ingredients
Potato cakes
- about 2 cups leftover baked potato mash (with garlic confit already mixed in)
- 1 egg
- ¼–⅓ cup flour
- 1 small shallot, very finely minced
- 2–3 green onions, thinly sliced
- Kosher salt and black pepper
- Chicken schmaltz
- 1 small knob butter
- Freeze-dried chives (optional)
Sriracha mayo
- ½ cup mayonnaise
- 1–2 Tsp sriracha (to taste)
- Squeeze of lemon or splash of rice vinegar
- Pinch of salt
Method
Shallot infusion
In a skillet over medium heat, add 1–2 Tbsp schmaltz and a small knob of butter. Add the minced shallot and a pinch of salt. Cook gently until the shallot is soft and lightly golden. Do not brown deeply.
Remove the shallots with a slotted spoon. Leave the infused fat in the pan and turn the heat off for now.
Mix the potato cakes
In a bowl, combine the leftover mash, egg, ¼ cup flour, sautéed shallots, green onions, and black pepper. Mix gently.
The texture should be thick, scoopable, and soft. Not stiff dough. If it is too loose, add 1–2 Tbsp more flour. If it is too dense, add a small splash of milk. Set aside.
Fry the potato cakes
Turn the skillet heat back to medium. Add a little more schmaltz if needed.
Scoop ¼–⅓ cup portions and form into thick patties (about ¾ inch thick). Place in the skillet.
Cook 4–5 minutes per side until deep golden brown. Do not rush the flip.
Make the sriracha mayo and serve
While the cakes fry (or before), stir together the mayonnaise, sriracha, lemon or vinegar, and salt. Taste and adjust the heat.
Remove the potato cakes to a plate. Sprinkle with freeze-dried chives if using. Serve with sriracha mayo on the side.
Notes, swaps, and guardrails
Why this works
- Schmaltz adds depth. Garlic confit in the mash adds background richness.
- Shallot and green onion give layered allium.
- Sriracha mayo bridges heat and acid.
I served this with
Roasted smoked turkey kielbasa and blistered green beans. Cut the kielbasa ring into 4 portions, slice each lengthwise, and roast cut-side down on a sheet pan at 425°F (220°C) for 20–25 minutes. Toss trimmed green beans with olive oil, salt, and pepper; spread on the other half of the pan. Everything finishes together if you start the sheet pan about 10–12 minutes before you begin frying the potato cakes.
The mash requirement
You need leftover baked potato mash with garlic confit already mixed in. If you do not have that, make Ultra-Concentrated Baked Potato Mashed Potatoes and fold in cloves from garlic confit before mashing. Plan ahead and make extra. The mash improves with a day in the fridge.
Texture of the potato mixture
Thick, scoopable, and soft. If you add too much flour, the cakes will be dense. If you add too little, they will fall apart in the pan. When in doubt, start with ¼ cup flour and add only if the mixture is visibly loose.
- Do not rush the flip on the potato cakes. Let the first side get deep golden before turning.
- Do not skip the shallot infusion. It seasons the schmaltz and adds layered flavor.
- Do not overcrowd the skillet. Fry in batches if needed.