Irish Cast Iron Skillet Corned Beef Colcannon Casserole

Start with a relatable hook I love comfort food that doubles as kitchen show-off material, and this Irish Cast Iron Skillet Corned Beef Colcannon Casserole fits the bill perfectly. Have leftover corned beef from St. Patrick’s Day? Perfect — I use leftovers all the time. Want something cheesy, hearty, and just a little bit smug to bring to a potluck? Yep, this is it.

Introduce the star ingredient Corned beef steals the show but the colcannon-style cabbage and potatoes give it that classic Irish hug. The cast iron skillet? That’s the secret to crispy edges and a cozy presentation.

Briefly state what the reader will get I’ll walk you through the ingredients, the method step-by-step, pro tips, tasty variations, storage hacks, and a few fun leftover ideas. Ready to get messy in the best way? Also, FYI, if you enjoy skillet meals you might like this similar recipe I tried recently: Asian-inspired beef and cabbage skillet — it taught me a lot about frying cabbage like a boss.

Why You’ll Love This Recipe

• Comfort food with Irish roots — creamy potatoes meet savory corned beef and cabbage.
• Leftover-friendly — use leftover corned beef and avoid sad fridge regrets.
• Cast iron magic — you get crisp edges and even heat without breaking a sweat.
• Feeds a crowd — big skillet, big smiles.
• Make-ahead friendly — assemble, refrigerate, bake later.

Ingredients You’ll Need

• 4 Tbl. butter
• 1/2 large onion, chopped
• 1/2 head cabbage, cut into 1″ pieces
• 1/4 tsp. regular salt
• 1/4 tsp. coarse ground black pepper
• 1/2 tsp. sugar
• 1 lb. coarsely chopped cooked corned beef (leftovers work great!)
• 1 1/2 – 2 lbs. red, Yukon Gold or russet potatoes, unpeeled and thinly sliced
• 16 oz. block swiss cheese, grated (4 cups)
• 2¼ cups whole milk
• 3/4 cup heavy cream
• ¼ cup mayo
• ⅓ cup flour
• ½ tsp. coarse ground black pepper, or to taste
• ½ tsp. garlic powder
• 1½ tsp. salt
• 1 tsp. spicy brown mustard
• ¼ tsp. onion powder
• sliced green onions for garnish if desired

How to Make (Step-by-Step)

Step 1 — Sauté the veg and cabbage

In a cast iron skillet over medium-high heat, melt butter with cabbage, onion, salt, pepper, and sugar. When the butter melts, cover, reduce heat to medium-low, and cook for 20 minutes or until cabbage becomes almost tender. Stir occasionally. If it starts to brown, lower the heat during the last 5 minutes.

Step 2 — Add the corned beef

Stir in the chopped meat and stir-fry a few minutes longer. Remove all with a slotted spoon to a bowl and set aside. I always taste a little — don’t judge me.

Step 3 — Prep the skillet and sauce

Preheat oven to 350º F. Wipe out the skillet and butter the insides and bottom with 1 Tbl. butter. If you use a 3-quart baking dish or dutch oven, grease with butter or butter-flavored spray.

In a large 4-cup measuring pitcher or medium bowl, whisk flour, salt, garlic powder, black pepper, mustard, and onion powder with milk, cream, and mayo until completely combined. This makes a luscious, slightly tangy sauce that holds everything together.

Step 4 — Slice and layer the potatoes

Using a mandoline (or a careful kitchen knife), slice potatoes into 1/8–1/4-inch slices. Layer one-third of the potato slices into the skillet. Sprinkle on one-third of the cabbage-meat mixture, then 1 cup of shredded swiss, then pour on one-third of the cream and milk mixture.

Repeat this twice more, adding 1 cup of cheese to the second layer and the last 2 cups of cheese to the top. Finish by pouring the last third of the cream mixture.

Step 5 — Bake to perfection

Cover skillet (or baking dish) with a lid or foil and bake for 1 hour. Remove lid or foil, and bake an additional 35–45 minutes or until potatoes become tender. Test with a knife: if the knife slides through the center like butter with no resistance, you nailed it.

Step 6 — Rest and garnish

Let the casserole rest for at least 20 minutes before serving. Longer if you can wait (I rarely can). Garnish with snipped green onion or chopped parsley if you like a little color.

Pro Tips for the Best Results

• Use unpeeled potatoes for texture and quick prep.
• Mandoline = consistency. Slice evenly for even cooking.
• Swiss cheese melts beautifully and gives a nutty tang — don’t skimp.
• Don’t rush the rest time. The casserole firms up so you can slice clean portions.
• Cast iron advantage: preheat your skillet slightly before assembly to help the bottom get a bit crisp.
• Adjust seasoning after you stir in the corned beef; leftovers vary in saltiness.
• Make ahead: assemble, cover, refrigerate up to 24 hours, then bake straight from the fridge (add 10–15 minutes to bake time).

Fun Variations & Topping Ideas

Variations:

• Swap swiss for cheddar if you like a sharper bite.
• Use leftover roast beef or shredded chicken for a different protein profile.
• Make it spicy: stir in 1–2 tsp. hot sauce or use pepper jack cheese.

Toppings:

• Crispy bacon bits for extra umami.
• Toasted breadcrumbs mixed with butter for a crunch.
• Pickled jalapeños for a tangy kick.
• A dollop of sour cream and chives at serving time for freshness.

Storing and Reheating

• Refrigerate leftovers in an airtight container for 3–4 days.
• To freeze, wrap tightly and freeze up to 3 months.
• Reheat slices in a skillet over medium-low heat for a crisp bottom, or reheat at 350º F in oven until warmed through.
• Microwave reheating? Fine for speed, but you’ll lose the crisp edge. I only microwave when desperate.

Leftover Ideas

• Turn leftover slices into melt sandwiches with extra cheese.
• Chop warmed leftovers and use as a hash topped with a fried egg.
• Make mini servings in muffin tins and bake until crispy for handheld snacks.
• Add a scoop to soup for instant heartiness — trust me.

Frequently Asked Questions (FAQ)

Can I use pre-shredded cheese?

Yes, but I prefer grating from a block. Pre-shredded cheese contains anti-caking agents that slightly change the melt and texture. If convenience wins, use pre-shredded.

Can I make this in a baking dish instead of cast iron?

Absolutely. I use a baking dish a lot when I don’t want to fuss with cleaning cast iron. Butter the dish well and expect minor differences in crispiness.

How do I prevent watery casserole?

Salt draws moisture from vegetables. Toss cabbage with a pinch of salt and squeeze out excess water before cooking if you worry about sogginess. Also, don’t overload the sauce.

Can I reduce dairy for a lighter dish?

You can reduce heavy cream or use lower-fat milk, but the casserole won’t be as creamy or indulgent. IMO, go for full-fat at least once.

Conclusion

This Irish Cast Iron Skillet Corned Beef Colcannon Casserole gives you cheesy comfort, smart use of leftovers, and that satisfying cast-iron finish we all secretly chase. It works for weeknights, potlucks, and lazy Sunday dinners. Try it, tweak it to your taste, and tell me which variation you loved. If you want the original recipe inspiration or need a quick reference, check out the classic version at Irish Cast Iron Skillet Corned Beef Colcannon Casserole — it’s a solid starting point.

Leave a comment and a rating below if you make this — I actually read them and I enjoy clever twists, so don’t be shy. Want more skillet ideas? I’ve got plenty and I’ll share the best ones if you ask. 😉

Corned Beef Colcannon Casserole

A hearty and cheesy casserole featuring leftover corned beef, potatoes, and cabbage, baked to perfection for a comforting Irish meal.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 1 hour hr 45 minutes mins

Total Time 2 hours hrs 5 minutes mins

Servings: 8 servings

Course: Dinner, Main Course

Cuisine: Comfort Food, Irish

Calories: 450

Ingredients Method Notes

Ingredients

  

Vegetables and Seasoning

• 4 Tbl. butter For sautéing
• 1/2 large onion, chopped
• 1/2 head cabbage, cut into 1-inch pieces
• 1/4 tsp. regular salt
• 1/4 tsp. coarse ground black pepper
• 1/2 tsp. sugar

Main Ingredients

• 1 lb. coarsely chopped cooked corned beef Leftovers work great!
• 1.5-2 lbs. red, Yukon Gold or russet potatoes, unpeeled and thinly sliced
• 16 oz. block swiss cheese, grated (4 cups)

Creamy Sauce Ingredients

• 2¼ cups whole milk
• 3/4 cup heavy cream
• ¼ cup mayo
• ⅓ cup flour
• ½ tsp. coarse ground black pepper or to taste
• ½ tsp. garlic powder
• 1½ tsp. salt
• 1 tsp. spicy brown mustard
• ¼ tsp. onion powder
• sliced green onions for garnish (if desired)

Method

 

Preparation

1. In a cast iron skillet over medium-high heat, melt the butter with cabbage, onion, salt, pepper, and sugar. Cover, reduce heat to medium-low, and cook for 20 minutes or until cabbage becomes almost tender, stirring occasionally.
2. Stir in the chopped corned beef and stir-fry for a few minutes longer. Remove all with a slotted spoon to a bowl and set aside.
3. Preheat the oven to 350º F. Wipe out the skillet and butter the insides and bottom with 1 tablespoon of butter.
4. In a large measuring pitcher or medium bowl, whisk together flour, salt, garlic powder, black pepper, mustard, and onion powder with milk, cream, and mayo until completely combined.

Assembly

1. Using a mandoline or careful kitchen knife, slice potatoes into 1/8–1/4-inch slices. Layer one-third of the potato slices into the skillet.
2. Sprinkle on one-third of the cabbage-meat mixture, then add 1 cup of shredded swiss cheese, and pour on one-third of the cream and milk mixture.
3. Repeat this twice more, adding 1 cup of cheese to the second layer and the remaining cheese to the top, finishing by pouring the last third of the cream mixture.

Baking

1. Cover the skillet with a lid or foil and bake for 1 hour.
2. Remove the lid or foil, and bake an additional 35–45 minutes or until potatoes become tender, testing with a knife.

Garnishing and Serving

1. Let the casserole rest for at least 20 minutes before serving. Garnish with green onion or parsley if desired.

Notes

Use unpeeled potatoes for texture. Don’t rush the rest time to allow the casserole to firm up. Assemble and refrigerate for up to 24 hours before baking. Adjust seasoning to taste based on corned beef saltiness.