The Ingredient That Makes Japan's 7-Eleven Egg Salad Sandwiches So Creamy

Convenience store food might not have the best reputation over in the United States, but in Japan, the 7-Eleven franchise offers quite a spread of widely-loved food options. One of the convenient grab-and-go meals available is the egg salad sandwich. The food starts with a fluffy, slightly sweet milk bread exterior, which is then filled with the soft, eggy filling.

The sandwich owes its creaminess, in part, to the way the egg filling is prepared. Rather than using whole hard boiled eggs, this version of the sandwich separates the whites from the yolks, creating a yolk-heavy version. Egg yolks are higher in fat than their egg white counterparts, making them extra creamy when blended together for a recipe.

This method also lends its color to the sandwich, creating a vibrant yellow filling that makes the sandwich as visually pleasing as it is delicious. While the filling is made much richer by the egg yolks, there is one other ingredient that truly elevates the mix.

Another huge reason that the sandwich is so deliciously creamy is thanks to the addition of Kewpie mayo. While a Western egg salad that's often made for backyard barbecues or potluck parties uses standard mayonnaise, Kewpie mayo changes up the flavor just enough to be noticeable.

There are a few major differences between regular mayonnaise and Kewpie mayo. For starters, Kewpie mayo features a slightly more tangy and sweet flavor. It's also slightly more acidic than the standard spread, adding a little bit of extra flavor to every bite. Thanks to the strong flavors, only a little bit is needed to enhance your meal, allowing the egg yolks to prevail as the star of the sandwich.

Though Kewpie mayo may be more popular in Japan where it originated, the condiment can be found stateside in plenty of Asian specialty food stores. Some major retailers, like Target and Walmart may even carry it, depending on the location. But if you can't find it in person, you can always order it online.

If you find yourself craving the sandwich after returning home from a trip to Japan, or you just want to taste test it without taking a trek across the globe, there's a way to recreate the popular sandwich at home thanks to a recipe from Food & Wine.

You'll need to start with the right base for the food. If you're planning ahead, you can bake up some Japanese milk bread to slice up for the sandwich. But if you'd prefer a quicker meal, you can swap in a fluffier, store-bought white bread.

When making the filling, hard boil the eggs. Once the shell has been removed, separate the egg whites from the yolks, and chop the egg whites separately. Then, mash the yolks along with your Kewpie mayo and selected seasonings, and add in a few of the egg whites. Once the filling has been thoroughly combined, throw in some heavy cream to smooth things out. Spread some butter on the sandwich bread for an extra indulgent taste, add your filling, and enjoy your sandwich.

While the at-home sandwich may not be a perfect recreation, the addition of Kewpie mayo and some extra egg yolks will make the meal super similar to the one you'd find in Japan.