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This Corned Beef Grilled Cheese is the ultimate St. Patrick's Day sandwich, made with buttery toasted bread, caramelized onions, melted cheese, and corned beef. Simple, flavorful, delicious!
This recipe creates a tasty and filling sandwich recipe, but if you're still in the mood to try even more sandwich recipes, then try making a Toasted Steak Sandwich, cheesy Grilled Cheese Sandwich, or Croque Monsieur.

Of course, you donโt need a recipe for a grilled cheese sandwich, but I have to share this combination because not only is it delicious but it also contains corned beef, Swiss cheese, and caramelized onions on buttery toasted rye bread.
A grilled cheese sandwich is the one thing that I love making on those evenings when I don't feel like spending much time in the kitchen. It's also the perfect thing to whip up when you don't feel like leaving the house to make a trip to the grocery store because you probably already have the main ingredients in your kitchen and that is bread and cheese.
What Kind of Bread?
The bread for this sandwich that I am going to use is some seeded rye bread that I was able to pick up in the bakery section of my grocery store. I love using bread from there because it's fresh and contains simple ingredients with fewer preservatives.
Feel free to use any bread that you prefer. Sourdough or white sandwich bread will also work just as well.
What Kind of Cheese for this Grilled Cheese Sandwich?
For the cheese, I prefer using some slices of Swiss cheese, but if you can find Jarlsberg cheese that would be amazing as well.
What Kind of Corned Beef Works Best?
Now if you have some corned beef that you've already prepared to celebrate St. Patrickโs Day, then feel free to thinly slice that and use it. But if you don't, then just grab some deli slices of corned beef and cut it into strips to add to the caramelized onions that you will sautรฉ before assembling the corned beef grilled cheese.
How Many Sandwiches will this recipe make?
This recipe makes enough for two grilled cheese sandwiches, so you can eat one and share the other. If you need more than two, then feel free to double or triple the recipe!
Let's get started.
Ingredients You'll Need
- Deli-sliced Corned Beef - Try selecting thinly sliced or shredded corned beef from the deli counter. You will need at least two ounces to make two sandwiches.
- Swiss Cheese - To make this grilled cheese sandwich I'm going to use Swiss cheese, but Jarlsberg cheese will pair well with the corned beef if it's available.
- Bread - For this recipe, I love using seeded rye bread, but feel free to use any bread that you prefer.
- Butter - You may use salted or unsalted butter depending on your preference to create the sauce and make the grilled cheese sandwiches.
- Onion - Any white onion or yellow onion will do.
- Worcestershire Sauce - Adds amazing savory and umami flavor to the sandwich.
- Mustard - Try using a grainy mustard.
- Sugar - You only need a small amount of granulated sugar or cane sugar to add a slight sweetness to balance the savory flavors. No worries, it will not make the sandwich taste sweet.
- Salt - This will help to season the onions and remove the excess moisture.
- Ground black pepper - Adds additional peppery seasoning flavor to the onion while cooking. Try using freshly cracked black pepper.
See the recipe card below for exact ingredient quantities and instructions.
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Step by Step Instructions
Begin the recipe using a large skillet over medium-high heat. Once warm, add the butter and allow it to melt before adding in the onion, sugar, salt, and ground black pepper. Cook the onion mixture stirring regularly until the onions are soft, translucent, and golden brown. About 10 to 15 minutes.
Carefully remove the skillet from the heat and stir in the corned beef, Worcestershire sauce, and mustard until combined. Set aside for a moment while you complete the next step.
Using four slices of bread, top each with a slice of cheese. Next, divide the corned beef mixture in half and place the mixture evenly on top of two slices of bread over the cheese. Cover the corned beef mixture with the other two slices of bread to create two sandwiches.
Using the same large skillet, return it to the stove over medium-high heat. Once warm, add the butter and allow it to melt before adding the sandwiches. If the skillet is not large enough to hold them both at the same time, then divide the butter in half and cook one at a time.
Once the bread has toasted on one side, use a spatula to flip it to the other side and press the sandwich down using the spatula as it cooks. Once the bread is toasted and the cheese has melted, carefully remove the sandwiches from the skillet. Serve warm and enjoy!
Best Recipe Tips & Tricks
- Use thick sliced Swiss cheese as it holds up better. If you prefer to use a different kind of cheese, try shredding it using a box cheese grater.
- Select the right skillet! I love using a cast-iron skillet to make grilled cheese sandwiches because it holds heat evenly and well. A non-stick skillet is a good alternative.
- Be sure to watch the heat and if you need to adjust it to a lower heat, then do so. You don't want your sandwich to cook too quickly and burn.
- Make sure that you use enough butter to coat the entire bottom of the pan before adding the bread. Once you flip, if you notice that you need more butter than suggested, then go ahead and add it.
Storage
This sandwich is best enjoyed shortly after it has been made while it is still warm. It does not store or reheat well and will become soggy.
Want More Sandwich Recipes? Try These:
- Roast Beef and Swiss Cheese Sandwiches
- Toasted Steak Sandwich
- Croque Monsieur
- Croque Madame
- Philly Cheese Chicken Sandwich
- Instant Pot Philly Cheesesteak
- Meatball Sub Sandwich
Have any comments, questions, or other delicious ways to enjoy this Corned Beef Grilled Cheese? Please share them in the comments below!
๐ Recipe
Corned Beef Grilled Cheese
Ingredients
- 1 ยฝ tablespoons butter, divided
- 1 small onion, thinly sliced
- 1 tablespoon sugar
- ยฝ teaspoon salt
- ยผ teaspoon ground black pepper
- 2 ounces deli-sliced corned beef, cut into strips
- 2 teaspoons Worcestershire sauce
- 1 tablespoon grainy mustard
- 4 slices Swiss cheese, or any you prefer
- 4 slices rye bread, or any you prefer
Instructions
- Using a large skillet over medium-high heat. Once warm, add ยฝ tablespoon butter and allow it to melt before adding the 1 small sliced onion, 1 tablespoon sugar, ยฝ teaspoon salt, and ยผ teaspoon ground black pepper.
- Cook the onion mixture stirring regularly until the onions are soft, translucent, and golden brown. About 10 to 15 minutes.
- Carefully remove the skillet from the heat and stir in the 2 ounces corned beef, 2 teaspoons Worcestershire sauce, and 1 tablespoon mustard until combined. Set aside for a moment while you complete the next step.ย
- Using 4 slices of bread, top each with a slice of cheese.ย Next, divide the corned beef mixture in half and place the mixture evenly on top of two slices of bread over the cheese. Cover the corned beef mixture with the other two slices of bread to create two sandwiches.ย
- Using the same large skillet, return it to the stove over medium-high heat. Once warm, add the 1 tablespoon butter and allow it to melt before adding the sandwiches.
- If the skillet is not large enough to hold them both at the same time, then divide the butter in half and cook them one at a time.
- Once the bread has toasted on one side, use a spatula to flip to the other side and press the sandwich down using the spatula as it cooks.
- Once the bread is toasted and the cheese has melted, carefully removed the sandwiches from the skillet and serve warm. Enjoy!ย
Video
Notes
- Use thick sliced Swiss cheese as it holds up better. If you prefer to use a different kind of cheese, try shredding it using a box cheese grater.
- Select the right skillet! I love using a cast-iron skillet to make grilled cheese sandwiches because it holds heat evenly and well. A non-stick skillet is a good alternative.
- Be sure to watch the heat and if you need to adjust it to a lower heat, then do so. You don't want your sandwich to cook too quickly and burn.
- Make sure that you use enough butter to coat the entire bottom of the pan before adding the bread. Once you flip, if you notice that you need more butter than suggested, then go ahead and add it.
Original post date 03/15/2017. Updated 03/11/2022 & 03/13/2024.
Tamara says
Goodness! I just sent this link to Cassidy. I really think it's brilliant. We don't have mustard but I think we have everything else so that's just one quick grab at the store.
admin says
Yay! Thank you! If you give it a try please let me know how it turns out for you ๐