Forget Tomato Soup — This Rustic Dipping Sauce Takes Your Next Grilled Cheese To Zesty New Heights

Grilled cheese pairs particularly well with tomato, whether it's a juicy red slice on the sandwich, a squeeze of ketchup on the side, or comforting tomato soup for dipping. That's because the fat in the cheese and the carbs in the bread make this dish a rich, filling meal, and the acidity of tomato soup cuts into that richness in perfect contrast. But tomato soup isn't the only zesty, acidic ingredient you should be pairing with your grilled cheese. Next time, try dipping it in whole grain or stone-ground mustard instead.

No, tomato soup and whole grain mustard don't taste the same, but they have similar elements: they each bring a savory, almost pungent bite (especially the mustard) that offers balance. Whole grain mustard's texture is far different from tomato soup, though. It's made with whole crushed mustard seeds, giving it a course texture, and it's much thicker. Whole grain or stone-ground mustard is not to be confused with Dijon, which is a common mustard that's creamy and smooth. Along with pops of crunchy texture, whole mustard also has a far more pungent flavor, so while you might pair a whole bowl of tomato soup with your grilled cheese, you'll probably only need about a tablespoon of this mustard; a little goes a long way.

It's fine to use whole grain mustard as a dipping sauce for any grilled cheese recipe you usually use. But for the best flavor, consider what cheese you put on the grilled cheese. You need a cheese that has a rich, creamy, almost nutty flavor profile to offer a balance that stands up to mustard's pungency. Sharp, aged cheddar would work well here thanks to its fat content and robust flavor. A creamy, slightly nutty cheese like Gruyère would also be a good option, as well as Asiago, which has a sweet, nutty profile.

If dipping the grilled cheese in mustard is too harsh for your tastebuds, spread a thin layer right on the inside of the sandwich so you get that subtle mustard acidity in each bite. You can also incorporate other flavors into the grilled cheese, like the sweet-meets-savory flavors of melt-in-your-mouth caramelized Spanish onions; they embody the richness and acidity that the cheese and mustard both bring for a well-rounded, robust sandwich.