Corned Beef Breakfast Casserole Recipe (with leftovers)

Give your corned beef leftovers a delicious makeover with this easy-to-make corned beef casserole recipe. This hearty casserole is perfect for breakfast or a weeknight dinner. Leftover corned beef never tasted so good!

If corned beef brisket is one of those things you only get to have one or two times per year, you definitely want to put all the yummy leftovers to good use. We love this gorgeous corned beef breakfast casserole and our Au Gratin Potatoes with Corned Beef as two fantastic ways to enjoy corned beef on day two.

Why You’ll Love this Corned Beef Breakfast Casserole 

• A delicious dish the whole family will love and one of our favorite ways to repurpose extra corned beef into a whole new meal.
• Quick and easy 15-minute prep time using simple ingredients.
• It can easily be customized by adding your favorite herbs, spices, or vegetables to suit your taste.
• This recipe is easy to prepare and can be made in advance and reheated when needed.

Ingredients you’ll need for this Corned Beef Casserole Recipe

• Corned Beef. We bake a large one just so we can make recipes just like this one.
• Yellow Onion. A sweet onion such as Vidalia will also work if needed.
• Garlic Cloves. Use fresh or frozen garlic. We don’t recommend preminced garlic in the jar.
• Green Bell Pepper. Red bell pepper or a medley of colors will work!
• Eggs. We use Grade A, large eggs.
• Milk. Use a combination of heavy cream and water in a 2:1 ratio if needed.
• Frozen Shredded Hashbrowns. Can be thawed or used frozen.
• Shredded Cheddar Cheese.
• Salt and Pepper. To taste. The corned beef will add a significant amount of salt, so you may want to salt the dish at the table as needed.

How To Make Corned Beef Casserole 

Please note, that the printable recipe card has ingredient quantities, complete instructions, and nutritional information. The following is a quick overview of the recipe.

Step One. Get everything ready.

Preheat the oven, spray your pan, and pull out all of the ingredients. This recipe is a great one to have kids help with too!

Step Two. Sauté the veggies.

Cook the onion and green pepper until softened. Add the garlic and saute for an additional 2 minutes.

Step Three. Whisk the eggs.

In a separate bowl, whisk eggs, milk, salt and pepper together.

Step Four. Mix the hashbrowns with corned beef.

In a large mixing bowl, combine the hashbrowns, corned beef, and 1-1/2 cups of the cheddar cheese. Stir to combine.

Step Five. Mix it all together.

Add the vegetable mixture and egg mixture into the mixing bowl with the hashbrown mixture. Stir to combine.

Step Six. Bake your Corned Beef Breakfast Casserole.

Pour into the baking dish, and top with the remaining cheese. Cover with aluminum foil and bake for 20 minutes. Remove foil and bake for an additional 10-15 minutes or until the casserole has started to brown.

Frequently Asked Questions

How do you know Corned Beef Casserole when is baked?

Look for bubbling at the edges and the cheese is melted and golden brown 

What is the best way to store Corned Beef Breakfast Casserole? 

Cover and refrigerate this casserole. Since this recipe is made with leftovers, you should eat or freeze it. within two or three days.

Can I freeze Corned Beef Casserole?

Yes, you can freeze the whole casserole or freeze individual slices. You can thaw and reheat the whole casserole in the oven. You can thaw and reheat individual slices in the microwave.

How to reheat leftover Corned Beef Casserole 

You can reheat refrigerated leftovers whole in the oven, or you can reheat individual portions in the microwave. One portion may take as little as thirty seconds to one minute in the microwave, depending on your machine. Do not overcook it in a microwave because the eggs will get chewy fast.

Serving Suggestions

Our easy corned beef casserole is a complete meal. However, we like serving our homemade sweet apple sauce and a slice of our Irish brown bread for a meal that will keep you satisfied for hours. If you’re serving this great recipe for dinner, a slice of Chocolate Stout Bundt Cake is a must!

Hostess Tips for the Perfect Leftover Corned Beef Casserole 

• Make ahead and refrigerate. You can leave it unbaked and bake it when you are ready for it (within 24 hours) or bake it and then reheat it when you are ready for it. Either way works.
• Cut corned beef into bite-sized pieces for easy eating.
• If the cheese starts to get to browned, cover it loosely with aluminum foil lightly sprayed with nonstick cooking spray. 
• If the hashbrowns are frozen, add 15 minutes to the baking time. You will know when the casserole is done when you fully cook the egg mixture and liquid does not pool under the ingredients.

Substitutions and Variations

The cheese you use should be semi-soft and one that melts well. Swiss cheese, parmesan cheese, or gouda cheese will work in place of cheddar. Even a Mexican blend works great or other purchased shredded cheese will work. Mix and match cheeses to your heart’s content.

Casseroles are a great way to add your favorite ingredients. Add leftover cabbage, herbs, or veggies of your choice.

If you boiled potatoes to go with your corned beef, substitute leftover sliced potatoes for the hashbrowns. 

Still looking for leftover recipes? Check these out!

• Corned Beef and Cabbage Soup is a hearty soup recipe that is a great way to use leftover ingredients.
• Corned Beef Sandwich combines a sweet mustard sauce with a crunchy slaw that puts this great sandwich over the top. Especially when you put it on Sourdough Rye Bread or Sourdough Pumpernickel Bread recipes!

I hope you enjoyed this delicious recipe as much as we do. Drop me a comment below, and don’t forget to give it a star rating. ⭐⭐⭐⭐⭐. Your comments and ratings help others decide if this recipe is for them too.

There’s nothing like a great casserole!

We love a good hearty casserole. If you’ve got potatoes, you’ve got the start of a delicious casserole. Just take a look at our Sweet Potato and Apple Casserole. It’s easy and so delicious. If you’ve got corned beef, you’ve got a gold mine of recipe choices.

Comforting Casseroles

• Beef Noodle Casserole from That Recipe
• Corned Beef Breakfast Casserole from Hostess at Heart
• Ham & Veggie Noodle Casserole from A Kitchen Hoor’s Adventures
• Hamburger Rice Hotdish (Casserole) from Art of Natural Living
• Lasagna with Cottage Cheese from Palatable Pastime
• Poppyseed Chicken Casserole from Jen Around the World

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