What do you do with leftover corned beef? You turn it into the ultimate Irish comfort food casserole. This Corned Beef Casserole layers tender sliced potatoes, savory corned beef, sweet shallots, and shredded Brussels sprouts in a creamy milk sauce, then finishes with golden, crispy Parmesan on top. It’s hearty, flavorful, and perfect for St. Patrick’s Day leftovers, cozy Sunday dinners, or an easy weeknight family meal. Think shepherd’s pie meets gratin rich, satisfying, and baked until bubbling and beautifully browned.
table of contents
Recipe Overview
- Prep Time: 15 minutes
- Cook Time: 50 minutes
- Total Time: 1 hour 5 minutes
- Servings: 6
- Calories: 440 kcal per serving
Ingredients
- 1 ½ lbs cooked corned beef, thinly sliced
- 1 lb russet potatoes, thinly sliced (¼ inch)
- 2 cups milk
- 2 tbsp butter
- 2 tbsp all-purpose flour
- 4 shallots, thinly sliced
- 3 cups Brussels sprouts, thinly sliced
- ½ cup shredded Parmesan cheese
Step-by-Step Instructions
1️⃣ Prep
Preheat oven to 425°F (220°C). Grease a 9×9” casserole dish.
2️⃣ Prepare Potatoes
In a saucepan, add sliced potatoes. Cover with milk and butter.
Bring to a boil, then simmer 8 minutes.
Turn off heat and let cool slightly.
Reserve milk mixture.
3️⃣ Layer the Casserole
Layer:
- Potatoes
- Corned beef
- Shallots
- Brussels sprouts
Repeat layers until ingredients are used.
4️⃣ Make Sauce
Whisk flour into reserved milk mixture until smooth.
Pour evenly over casserole.
5️⃣ Bake
Top with Parmesan.
Bake 50 minutes until golden brown and bubbly.
Rest 15 minutes before slicing.
Flavor Notes
- The Brussels sprouts add earthy balance.
- Shallots give gentle sweetness.
- Parmesan creates a crisp, salty crust.
- Corned beef brings bold, savory depth.
Nutrition (Per Serving)
| Nutrient | Amount |
|---|---|
| Calories | 440 kcal |
| Protein | 26g |
| Carbs | 27g |
| Fat | 26g |
| Saturated Fat | 11g |
| Fiber | 3g |
| Sodium | 1599mg |
Nutrition is estimated and may vary.
Disclaimer
The nutrition information provided is an estimate calculated using online tools and may vary depending on ingredients and portion sizes. It is not intended as medical or dietary advice.
Can I use leftover corned beef?
Yes — this recipe is perfect for leftovers.
Can I substitute Brussels sprouts?
Yes. Try shredded cabbage or spinach.
Can I make it ahead?
Yes. Assemble and refrigerate up to 24 hours before baking.
Corned Beef Casserole
Ingredients
Equipment
Method
- Preheat oven to 425°F (220°C). Lightly grease a 9×13-inch baking dish.
- In a saucepan, combine sliced potatoes, milk, and butter. Bring to a gentle simmer and cook for about 8 minutes until slightly tender.
- Layer half of the potatoes in the baking dish, followed by corned beef, shallots, and Brussels sprouts. Repeat layers with remaining potatoes and ingredients.
- Whisk flour into the warm milk mixture until smooth. Pour evenly over the layered ingredients.
- Sprinkle Parmesan cheese over the top. Bake for 50 minutes until golden and bubbly. Let rest briefly before serving.
Nutrition
Notes
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Let us know how it was!Conclusion
Corned Beef Casserole is the kind of dish that transforms simple leftovers into something truly special. Creamy potatoes, savory corned beef, and crisp Parmesan create layers of rich Irish flavor in every bite. Whether you’re celebrating St. Patrick’s Day or simply craving hearty comfort food, this casserole delivers warmth, tradition, and pure satisfaction straight from the oven.