The Sweet And Savory Ingredient That Adds A Rich Flavor To Egg Salad

There's something rather humble about the classic and creamy egg salad sandwich. Maybe its because its base is so simple; hard-boiled eggs, a squirt of mayonnaise, and a little bit of mustard to give it an edge. These all come together to make this easy, lunchtime favorite. But, don't let its rudimentary recipe fool you into thinking that it can't be upgraded, especially with one ingredient in particular. 

Caramelized onions are your secret weapon in crafting an egg salad that has both savory and sweet flavor profiles intertwined with those mashed yolks. The caramelization process transforms what would otherwise be a sharp, biting, and rather unapproachable allium into something that's much more complex. This sophisticated addition can be as dressed up or dressed down as you like — meaning that you can play with the ratio of onions to eggs to find one that works for you. 

A good place to start is with four cups of raw onions for every dozen eggs. If that seems like a mind-bogglingly large amount of onions, fear not. As they cook down, they will reduce in size and become limp. You'll also want to be sure that your onions are cool when they go into your salad. Otherwise, you'll risk some temperature conflict between your cold mayonnaise and mustard and slightly steamy onions. 

Making caramelized onions is, in short, an act of both love and of patience. To make a batch of foolproof caramelized onions, you should expect to be standing by the stovetop for close to an hour. This will give the alliums ample time to intermingle with the broth and fat and slowly lose their rigid shape and biting flavor. You'll be rewarded with a plate of onions that you can not only use for your egg salad, but also repurpose for other recipes, like tossing into a pasta or adding to your pulled pork sandwiches.

There are also numerous ways out there to add extra flavor to your batch of caramelized onions that will make them more compatible with your sandwich elements. For example, you can try cooking your onions in leftover bacon grease to give them a meaty flavor and some residual saltiness. You can also use balsamic vinegar to both expedite the cooking time and give your onions a more mature flavor that will pair just as well with a standard egg salad sandwich as one brimming with herbs and spices.