Sous Vide Egg and Mashed Potato Jars Make Brunch a Hands-Off Affair

Jar up your leftover mashed potatoes with a freshly cracked egg, then cook them sous vide for a low-effort, high-reward brunch.

Overhead of two potato-egg jars on plates with toast, and a plate of bacon in the background, along with a glasses of orange juice and a cup of coffee.
Photographs: Vicky Wasik

When it comes to cooking and hosting brunch for a crowd, especially around the holidays, I'm in total agreement with Stella: Keep things simple and as low-effort as possible. The last thing you want to do after prepping, cooking, hosting, and cleaning up a big holiday dinner is to wake up early the next morning and start taking breakfast orders, slinging eggs for bleary-eyed out-of-town guests who've drained the pot of coffee you brewed before you had a chance to pour a cup for yourself.

For the baking crowd who love a sweet start to the day, Stella's cinnamon rolls, triple-pistachio buns, or DIY-Nutella rolls are all great prep-ahead, crowd-pleasing brunch options. But what about those of us who prefer a savory brunch, but don't feel like toiling over the griddle all morning or dealing with the anxiety of flipping a Spanish tortilla while hungover? Well, let me introduce you to these sous vide egg and mashed potato breakfast jars—the perfect hands- and brains-off dish for a post-holiday brunch.

Closeup of a spoonful of potato and egg with crispy chopped bacon.

I was recently introduced to the restorative properties of this egg-and-potato breakfast jar concept when my wife and I traveled to Las Vegas for a wedding. The morning after a wedding is never pretty, but it's way worse in Vegas in the middle of August. In desperate need of sustenance and ibuprofen, we hit up the ever-popular Eggslut for breakfast sandwiches and their signature dish, the questionably named but unquestionably delicious "Slut," a jar of creamy mashed potatoes with a poached egg nestled on top of the spuds.

Closeup side view of toast being dipped into a potato-egg jar, breaking the custardy egg yolk.

The egg gets a sprinkling of chives and flaky sea salt, and is served with a few toast points for dipping into the custardy egg yolk and potatoes. It's an incredibly satisfying and simple dish, one that I couldn't wait to recreate once I escaped the sensory-overload nightmare of the Strip.

Overhead of four Mason jars, each filled with mashed potatoes and an uncooked egg.

Despite my desire to keep my eyes closed that morning, I had taken note of the cooking process for the Slut. While outward appearances made these eggs seem like they'd been prepared en cocotte, what I saw instead was a cook gently lower a batch of fifty or so jars into a sous vide water bath to cook the eggs and reheat the mashed potatoes in one fell swoop. It's pretty neat that the temperatures for these two cooking tasks line up—sous vide eggs are perfectly custardy when cooked at 145°F (62.5°C), which is also in the ideal range for reheating mashed taters.

Closeup side view of four cooked mashed potato egg jars.

I have a long and checkered history with sous vide cooking, and particularly sous vide egg jars. When I worked on this sous vide cookbook during my time at America's Test Kitchen, I had to fight tooth and nail to convince my editors that Starbucks-style sous vide egg bites are an abomination that nobody should have to suffer through.

These potato-egg jars, on the other hand, are delightful, and show off the best attributes of sous vide—hands-off cooking that can be easily scaled up or down to fit your needs, with the textural advantages that precise temperature control can provide.

A bowl of mashed potatoes next to a sous vide water bath and Mason jars.

With only two essential components—mashed potatoes and eggs—this dish is perfect for the morning after a big holiday meal, when fridges are often filled up with Tupperware containers of leftovers, mashed potatoes being one of the usual suspects in that mix.

Overhead of set-up and ingredients for sous vide mashed potato egg jars, with an immersion circulator water bath, Mason jars, mashed potatoes, a carton of eggs, and chives.

To make these breakfast jars, start by setting up an immersion circulator, and bring a water bath to 145 degrees. Grab a carton of eggs, some leftover mashed potatoes, and some widemouthed Mason jars (eight-ounce jars are ideal). If you didn't make the mashed potatoes yourself and can't vouch for their seasoning, now is the time to fix that. Give them a taste, and adjust with salt and pepper as needed, adding a splash of milk or cream if they seem a little too stiff.

Overhead of dividing mashed potatoes between four Mason jars.

Divide the potatoes evenly among the jars, filling them about two-thirds of the way before gently pressing and smoothing them into an even layer with a small spatula or the back of a spoon.

Spooning mashed potatoes over gravy in a Mason jar.

If you have some extra gravy kicking around in the fridge, you can also bump up the savory richness of the dish by spooning a tablespoon or two into the bottom of the jars before adding the potatoes. Mashed potatoes, gravy, and gooey, runny eggs? That won't suck, trust me.

Cracking an egg into a Mason jar with mashed potatoes.

Crack an egg into each jar, but hold off on seasoning them for the moment. Sprinkling them with salt now will cause a pellicle to form on the surface of the egg yolks as they sit in the water bath, which isn't ideal.

Sealing the lid of a Mason jar so that it is fingertip tight. Over-tightening the lids can cause the jars to crack.

Pop the lids on the jars and lightly screw them on until they are just "finger-tight." Do not over-tighten the lids, as this can cause the jars to crack during cooking, which will make this easy-breezy brunch decidedly unchill.

Placing a Mason into the sous vide water bath by hand.

Carefully lower the jars into the water bath, using your hands if your fingers have been de-sensitized to heat over the years like mine, or with a pair of canning tongs. Make sure that the jars are fully submerged, set a timer for one hour, then walk away.

Pulling a Mason jar out of the sous vide bath with a pair of canning tongs.

Go back to bed. Or you could use that time to make a second pot of coffee, put away the clean plates from the dishwasher, and maybe even cook a batch of crispy-but-not-too-crispy bacon for your brunch buddies if you're feeling magnanimous.

Sprinkling chives over eggs.

Once that hour is up, pull the jars out of the water bath, unscrew the lids, season up the eggs with some sea salt and freshly ground black pepper, and finish them with a sprinkling of chives and chopped bacon if you went that route. Serve them with toasted bread for dipping, and bask in the afterglow of this perfectly simple, crowd-friendly brunch. Now you just have to figure out how to get those houseguests out of your hair before dinner time rolls around.

Side view of a potato-egg jar with added chopped crispy bacon.