This Crispy Baked Corned Beef and Potato Casserole is a hearty comfort-food dinner made with tender potatoes, savory corned beef, onion, garlic, creamy sauce, melted cheese, and a crisp golden topping. It is an easy way to transform leftover corned beef into a warm family meal that works for busy weeknights, Sunday dinner, or the days after a holiday celebration.
The potatoes become soft and creamy in the center while the top bakes until browned and slightly crunchy. Corned beef adds plenty of salty, seasoned flavor, so the casserole needs only simple herbs and careful seasoning. Serve it with cabbage, green beans, peas, roasted carrots, or a crisp salad.
Why You Will Love This Recipe
This casserole uses affordable ingredients and can be assembled in one baking dish. It is filling enough to serve as a complete meal, but it also pairs well with simple vegetables.
It is especially practical when you have leftover cooked corned beef. The meat can be chopped or shredded and layered directly with the potatoes. Canned corned beef can also be used for a faster pantry-friendly version.
The crispy topping provides texture, while the creamy sauce keeps the potatoes from becoming dry. The recipe can also be prepared ahead and baked when needed.
Ingredients
- 2 pounds Yukon Gold or russet potatoes, peeled and thinly sliced
- 2 cups cooked corned beef, chopped or shredded
- 1 small yellow onion, finely chopped
- 2 cloves garlic, minced
- 2 tablespoons butter
- 2 tablespoons all-purpose flour
- 1 1/2 cups whole milk
- 1/2 cup beef broth
- 1 teaspoon Dijon or yellow mustard
- 1/2 teaspoon dried thyme
- 1/2 teaspoon black pepper
- 1 1/2 cups shredded cheddar cheese, divided
- 1/2 cup breadcrumbs or crushed buttery crackers
- 1 tablespoon melted butter
- Chopped parsley or green onions for garnish
Ingredient Notes
Potatoes: Yukon Gold potatoes hold their shape and create a creamy texture. Russets become softer and absorb more sauce. Slice the potatoes evenly so they cook at the same rate.
Corned beef: Leftover brisket-style corned beef gives the casserole the best texture. Chop it into small pieces or pull it into short shreds. Canned corned beef works, but it is softer and usually saltier.
Cheese: Sharp cheddar balances the richness of the sauce. Swiss, Monterey Jack, Colby, or a combination of cheeses can be substituted.
Breadcrumb topping: Breadcrumbs create a crisp surface. Crushed crackers, panko, or crushed potato chips can also be used.
How to Prepare the Potatoes
Slice the potatoes approximately one-eighth inch thick. A mandoline makes uniform slices quickly, but always use its safety guard.
To ensure the potatoes become tender, place the slices in a pot of salted simmering water and cook for approximately five minutes. Drain thoroughly before assembling. This brief precooking step reduces the risk of firm potatoes in the finished casserole.
How to Make Corned Beef and Potato Casserole
- Preheat the oven to 375°F. Lightly grease a 9-by-13-inch baking dish.
- Partially cook the sliced potatoes for five minutes, then drain and set aside.
- Melt two tablespoons of butter in a skillet over medium heat.
- Add the onion and cook for four to five minutes, until softened.
- Add the garlic and cook for approximately 30 seconds.
- Sprinkle the flour over the onion mixture and stir for one minute.
- Gradually whisk in the milk and beef broth.
- Add the mustard, thyme, and black pepper.
- Cook over medium-low heat until the sauce thickens slightly.
- Remove the skillet from the heat and stir in one cup of cheddar cheese.
- Arrange half of the potatoes in the prepared baking dish.
- Spread the corned beef evenly over the potatoes.
- Pour half of the cheese sauce over the meat.
- Add the remaining potatoes and pour the rest of the sauce over the top.
- Sprinkle with the remaining cheddar cheese.
- Combine the breadcrumbs with one tablespoon melted butter and scatter them over the casserole.
- Cover loosely with foil and bake for 30 minutes.
- Remove the foil and bake for another 20 to 25 minutes, until bubbling and golden.
- Rest for 10 minutes before serving.
How to Make the Top Extra Crispy
Use panko breadcrumbs or crushed crackers and mix them with melted butter before adding them to the casserole. Bake uncovered during the final portion of cooking.
For deeper browning, broil the casserole for one to two minutes at the end. Watch it constantly because the topping can burn quickly.
How to Prevent a Watery Casserole
Drain the potatoes thoroughly after precooking. Simmer the sauce until it lightly coats the back of a spoon before layering it into the baking dish.
Allow the casserole to rest after baking. This gives the sauce time to thicken and prevents it from running across the plate.
Easy Variations
For a cabbage variation, sauté two cups of thinly sliced cabbage with the onion before making the sauce.
For a Reuben-inspired casserole, add drained sauerkraut and replace some cheddar with Swiss cheese. A small amount of Thousand Island dressing can be stirred into the sauce.
For extra vegetables, add peas, carrots, spinach, mushrooms, or bell peppers. Cook watery vegetables before layering them into the casserole.
For a spicier version, add cayenne, hot sauce, chopped jalapeños, or Pepper Jack cheese.
For a gluten-free casserole, use gluten-free flour or cornstarch to thicken the sauce and choose gluten-free breadcrumbs.
What to Serve with This Casserole
Serve the casserole with steamed cabbage, roasted Brussels sprouts, green beans, peas, carrots, broccoli, or a crisp garden salad.
It also pairs well with mustard, pickles, rye bread, dinner rolls, or a light vinegar-based slaw.
Make-Ahead and Storage
The casserole can be assembled up to one day ahead. Cover and refrigerate it before baking. Add approximately 10 extra minutes to the covered baking time when it goes into the oven cold.
Store cooled leftovers in an airtight container in the refrigerator for up to three to four days.
Reheat individual portions in the microwave, or warm the casserole in a 350°F oven until hot. The oven provides the best topping texture.
Freeze baked portions for up to two months. Thaw overnight in the refrigerator and reheat covered, then uncover briefly to crisp the top.
Printable Recipe Card
Crispy Baked Corned Beef and Potato Casserole
Prep Time: 25 minutes
Cook Time: 55 minutes
Resting Time: 10 minutes
Total Time: 1 hour 30 minutes
Yield: 6 to 8 servings
Category: Dinner
Quick Instructions
- Precook the sliced potatoes for five minutes and drain.
- Cook onion and garlic in butter.
- Add flour, milk, broth, mustard, thyme, and pepper.
- Thicken the sauce and stir in cheddar.
- Layer potatoes, corned beef, sauce, and cheese.
- Top with buttered breadcrumbs.
- Bake covered for 30 minutes, then uncovered for 20 to 25 minutes.
- Rest for 10 minutes before serving.
Final Thoughts
This Crispy Baked Corned Beef and Potato Casserole turns simple potatoes and leftover corned beef into a creamy, cheesy dinner with a golden, crunchy finish. Precook the potatoes briefly, thicken the sauce before assembling, and bake uncovered at the end for the best texture.
Serve it with vegetables, salad, cabbage, or warm bread for a satisfying family meal that is easy to prepare and even easier to enjoy.