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Corned beef might seem pretty synonymous with St. Patrick’s Day (for Americans, at least!) but the truth is it’s something you should be enjoying all year long. This recipe takes that salty, spiced brisket and pairs it with tender cabbage and onions, an amazing mustard spread, Dubliner cheese, and a deliciously savory Guinness au jus for a sandwich that takes its cues from both a Reuben and a French dip and yet still manages to celebrate all things Irish. Take a look!

Now, don’t let the long cooking time on the corned beef scare you away. It’s done in a slow cooker and is something you can do overnight (or even a day or two ahead) so it’s not something you’re going to have to worry about or fuss over. You can even use leftover or storebought corned beef if needed – as long as the end result is this amazing sandwich, you’ll be happy.

What makes this really special is how the components all come together. The mustard sauce is unique and so delicious – with an intense zip and a subtle sweetness that echoes the natural sweetness from the slow-cooked cabbage. Dubliner cheese is the perfect component to tie together those flavors with the rich and salty corned beef, but what really takes it over the top is the Guinness au jus. It doesn’t taste like beer, the Guinness just adds a richness and depth of flavor that mingles with the corned beef cooking liquid for a savory dipping sauce that you won’t be able to get enough of.

Serves 6-8

5m prep time

20m cook time

8h inactive

Rated 5 out of 5
Rated by 2 reviewers

Allergens: Gluten

For the Corned Beef:
  • 3 to 4 lbs corned beef
  • 1/2 head green cabbage, sliced
  • 1 yellow onion, sliced
  • 1 pint Guinness beer
For the Irish Mustard Sauce:
  • 1 tablespoon cornstarch
  • 1 teaspoon granulated sugar
  • 1 teaspoon dry mustard
  • 1/2 teaspoon salt
  • 1 cup water
  • 1 tablespoon butter
  • 1/4 cup apple cider vinegar
  • 1 teaspoon prepared horseradish
  • 2 egg yolks, beaten
For the Au Jus:
  • 1/2 tablespoon olive oil
  • 1 tablespoon diced shallots
  • 1 clove garlic
  • 1 cup Guinness beer
  • 1/4 cup broth from cooking corned beef
  • 2 teaspoons pickling spices
  • 1/4 cup Worcestershire sauce
For assembling:
  • Sliced pumpernickel or rye bread
  • Dubliner cheese, sliced
  • Kerrygold butter
For the Corned Beef:
  1. Arrange onion and cabbage in the bottom of slow cooker. Place corned beef on top. Cover with Guinness and enough water to cover meat completely. Sprinkle corned beef spices over the top. Cook on low 8-9 hours.
For the Irish Mustard Sauce:
  1. In a small saucepan, combine corn starch, sugar, dry mustard, salt, and 1 cup water over medium-low heat. Bring to a simmer and let bubble until thickened.
  2. Add butter, apple cider vinegar, and horseradish. Add a couple of spoonfuls of warm liquid from saucepan to egg yolks to temper, then stir egg yolks into saucepan.
  3. Cook at a low simmer whisking frequently until thickened, reducing heat if needed. If a thicker consistency is desired, add cornstarch 1 teaspoon at a time. Remove from heat and set aside.
For the Au Jus:
  1. In a skillet over medium heat, heat olive oil. Once hot, add shallots and cook until softened, 3-5 minutes. Stir in garlic and cook for one minute. Add Guinness, Worcestershire, pickling spices, and 1/4 cup liquid from slow cooker, or more if necessary. Simmer 20 minutes.
To assemble:
  1. Slice corned beef into thin slices.
  2. Heat a skillet to medium heat. Butter bread on both sides and grill in skillet until both sides are golden brown.
  3. Spread Irish Mustard Sauce on the inside of two slices of bread. Add corned beef. Top with cabbage and onions, followed by Dubliner cheese. Serve with au jus and enjoy!

Recipe adapted from Food Network, Vindulge, and All Recipes.

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