My grandmother used to make this growing up during the summer months and it was always fork tender and filling. Just 3 simple ingredients from the pantry.

4. Remove the foil and continue baking for 20 to 30 minutes more, until the potatoes are fork tender and the top is browned around the edges.

Baked corned beef potato casserole browned on top

5. Let the bake rest for 10 minutes before serving so the layers settle and scoop more neatly.

Variations & Tips

Add a little moisture: If your potatoes are especially starchy or sliced a bit thicker, add a few spoonfuls of water to the dish before covering and baking. That little bit of steam helps everything soften nicely.

Try a richer top: If you keep cheese on hand and do not mind going beyond three ingredients, a light sprinkle of shredded cheddar over the top during the last 10 minutes of baking makes a lovely browned crust.

Corned beef potato bake with melted cheddar on top
Corned beef potato bake with melted cheddar on top

Slice evenly: Thin, even potato slices are the secret to that fork-tender texture. A sharp knife works fine, but a mandoline makes the job quicker and helps the layers cook at the same pace.

Make it ahead: You can assemble the dish a few hours ahead of time, cover it, and refrigerate it until baking. That makes it especially handy for busy summer days when supper needs to be simple.