Horseradish Mayo Is The Hero Ingredient To Elevate A French Dip Sandwich

It's hard to beat a well-made French dip sandwich: Thinly sliced roast beef with melty Swiss cheese and caramelized onions on a soft but toasty French roll served with savory au jus that drips off the freshly dipped sandwich. It really is one of the best sandwiches of all time.

It's precisely the harmonious balance of these elements (meat, cheese, bread, and hearty beef juices) that makes the French dip such a classic. But, for as good as it is, what if it could be even better? What if there was something that could elevate this tried and true sammie to legendary status?

Horseradish mayo could be that hero ingredient, adding not one but two bold and startling deviations into the mix. First, there's the spicy bite of the horseradish, bringing a level of heat to this beloved American diner fare. Then, there's the creamy richness of the mayo, sliding in a silky new textural facet to this sandwich of non-French origins with a controversial history.

You might think, "If it ain't broke, don't fix it," but just think of the Philly cheesesteak. That sandwich features onions and melted cheese sauce, but did it stop there? No. Sometimes, a Philly cheesesteak is served with peppers and mushrooms, and that version might be even better. Sure, it'll never replace the classic, but this magical variation deserves its spot in the pantheon of sandwiches as well. So, why not update the French dip, too, with a little kick of horseradish mayo?

You may or may not know that horseradish is a root vegetable (it looks kind of like ginger) from the Brassicaceae aka mustard family along with its spicy cousins wasabi and radish. Typically used as a condiment, horseradish is grated or ground up and either made into its own sauce or added to creamy favorites like sour cream, mayo, and crème fraîche to bring a little heat to everything from bloody marys to soups and roast dinners.

The easiest way to make horseradish mayo is to buy pre-made horseradish sauce and add it to your favorite brand of mayonnaise. A little goes a long way, so it's best to start small and work your way up until you achieve your desired flavor-to-heat balance.

Or, go DIY and procure fresh horseradish. This route requires you to wash and peel the root vegetable's outer layer with a potato peeler or knife before grating it down. Just take note — fresh horseradish is much more pungent and spicy than its store-bought counterpart. Be advised to only use about half as much fresh horseradish as you would of the pre-prepared versions. While you might not want horseradish mayo on every French dip you make, it is something you should try at least once. Let horseradish mayo be your hero — if just for one day.