The Surprising Ingredient You Should Add to Grilled Cheese

It's likely already in your fridge.

Grilled Cheese Stack
Photo: Rebecca Longshore

In honor of National Grilled Cheese Day (celebrated each April), we cooked up more than a dozen different riffs on the classic toasty cheese sandwich. In a casual office poll, there were passionate pleas and many strong opinions ranging from the type of bread to the cheese itself—and even the preparation of the cheese before grilling. You'll find some of our staff's favorite combos below, but there was one grilled cheese secret ingredient that outshone all others. And, believe it or not, it wasn't bacon.

It was mustard. Senior Fashion Editor Rebecca Daly writes:

"My college roommate's mother taught me the undeniable importance of buttering BOTH sides of the bread (YUM). And my personal favorite combo is smoked gouda, a good grainy mustard, and very thinly sliced apple (and sometimes some onion). Drooling."

Rebecca had us at "buttering BOTH sides," but when she suggested a smear of grainy mustard, we had to give it a try. An assertive grainy Dijon offers a punch from ground mustard seeds similar to horseradish, plus salt and vinegar—all the bracing flavors a deliciously greasy butter, bread, and cheese sandwich needs to make it sing. Why do you think a grilled cheese tastes so good dunked in a bowl of sweet and tangy tomato soup? On its own, grilled cheese is pretty decadent—nutty from the toasting of the fat-soaked bread and slightly sweet from the bread itself (since most sandwich bread leans sweet to please our American palates). Sharp mustard balances those flavors and cuts some of the richness, turning a humble weekend lunch into a celebration dinner (or even party-worthy appetizer).

A secret mustard layer was delicious with thinly sliced apples like Rebecca suggested, but it worked equally well with a favorite like Cheddar, bacon, and tomato on seven-grain bread. You can't go wrong with a cheese and mustard sandwich—add a little swipe to any of your go-to grilled cheese variations. If that doesn't float your boat, we have plenty of other clever and delicious suggestions to share. Happy grilling!

Grilled Cheese Sandwich Variations Loved by Real Simple Staff

"Tomato and bacon!"Brigitt Earley, Deputy Editor

"Not sure if this is too far afield, but one of my favorite dinners is a few thin slices of brie, a slice or two of smoked turkey breast, and a few thin slices of pear (or apple). I put them on a grill pan, usually with sourdough bread, and just put something on top for a bit to smush (scientific) it all down. I also like to grate Gruyère and cook it with some arugula and good bread. THAT is a grilled cheese, and greens make it healthy."Laura Schocker, Digital Director

"I like Swiss cheese on whole wheat! But the secret for me is to sauté the bread in butter, then flip it when brown and put the cheese on the already browned side. Then, when the cheese is melty, put the halves together and press. Let brown a little more, then flip and press. Then, yum. Buttery, cheesy goodness, and Swiss is nice and stretchy."George Kimmerling, Executive Managing Editor

"Rye bread with a light spreading of truffle ghee and American cheese on a grill pan."Betsy Goldberg, Deputy Editor

"Whole wheat bread (holds up better IMO), mayo on the outside, a little butter spread on the inside, and then I only use blocked extra sharp cheddar (the sharpest I can find), which I cut into slices! I'm a purist—no veggies or meat inside for me!"Nora Horvath, Editorial Assistant

"Straight Cheddar slices with thinly (salted and peppered) slices of tomato inside and mayo on the outside. Even better if it's pressed in a griddle or George Foreman! If I'm feeling fancy, I'll get a couple of slices of sweet bread like brioche or Puerto Rican/Hawaiian bread. The sweet and salty flavors are 100. Also LOVE making grilled cheese with pimento and cheese spread under the broiler."Brandi Broxson, Associate Editor

"I like them with ricotta, mozzarella, and basil."Savannah James, Fashion Assistant

"Texas toast spread with mayo and sprinkled with some salt plus American cheese plus grated pepper jack plus salted tomatoes. AND butter in the skillet. Side note I made grilled cheese in a panini press once, and the results were truly 3x as delicious."Heath Goldman, Associate Food Editor

"Challah or whole wheat, grated Cheddar, tomato, and that tub butter w/ olive oil in it."Sara Austin, Executive Editor

"I love to add a slice of tomato. And always a pickle on the side. And I like to cut mine diagonally."Heather Muir, Beauty Director

"Kerrygold aged Cheddar is my favorite. Also, I love a good whole-grain bread or sourdough with grilled cheese. Butter over mayo, always. If I'm feeling really fancy, Brie grilled cheese with very thin slices of a Granny Smith apple. Or sharp Cheddar and peach with a little honey and walnut action. Now, that is my summer jam. Oh, also BACON JAM makes everything taste better."Rebecca Longshore, Social Media Manager

"Being a southern girl I like grilled pimento cheese. It's been a great source of happiness for me that Whole Foods in NY now sells PC. I was importing it from Kentucky."Dana Points, Contributing Editor

Was this page helpful?
Related Articles