This oven baked 3-ingredients white cheddar corned beef penne is one of those cozy, no-fuss dinners that feels like a hug in a casserole dish. My grandfather was born and raised in Dublin, and when he moved to the States he brought this simple little comfort meal with him. He’d make it on cold, gray evenings using pantry basics: leftover corned beef, a block of sharp white cheddar, and whatever pasta was around. I’ve streamlined his idea into a busy-weeknight-friendly bake that still gives me all the same warm, nostalgic vibes. It’s rich, cheesy, salty in the best way from the corned beef, and it goes straight from oven to table in one dish—perfect for when you want something that tastes like it took all afternoon, but really didn’t.
Serve this white cheddar corned beef penne straight from the glass casserole dish with a big green salad (I like mixed greens with a tangy vinaigrette to cut through the richness) and some crusty bread or garlic toast to scoop up the extra melty cheese from the corners. A simple steamed vegetable like broccoli or green beans works well on the side, and if you enjoy a drink with dinner, a crisp hard cider or a light beer pairs nicely with the salty corned beef and creamy cheddar. Leftovers reheat beautifully, so it also makes a great prep-ahead lunch for the next day.
Oven Baked 3-Ingredients White Cheddar Corned Beef PenneServings: 4
Ingredients
12 oz dry penne pasta
3 cups shredded sharp white cheddar cheese, divided
2 cups cooked corned beef, chopped into small chunks
1/2 cup reserved hot pasta cooking water (optional, for easier mixing and extra creaminess)
Nonstick cooking spray or a little butter, for greasing the dish
Directions
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch glass casserole dish with nonstick cooking spray or a little butter so the pasta and cheese don’t stick.
Bring a large pot of salted water to a boil. Add the penne and cook until just al dente, 1 to 2 minutes less than the package directions, since it will continue cooking in the oven. Before draining, ladle out about 1/2 cup of the hot pasta water and set it aside. Drain the pasta well.
While the pasta cooks, chop the cooked corned beef into small bite-size chunks. You want visible pieces so you get those classic pink, salty bites in every scoop of the casserole.
In a large mixing bowl, combine the hot drained penne, chopped corned beef, and 2 1/2 cups of the shredded white cheddar cheese. If the mixture seems a little dry or hard to stir, splash in a few tablespoons of the reserved hot pasta water at a time, just until everything is coated and starting to look creamy and melty.
Transfer the cheesy pasta and corned beef mixture into the prepared glass casserole dish, spreading it out into an even layer so the pasta reaches all the corners. Sprinkle the remaining 1/2 cup shredded white cheddar evenly over the top for a golden, bubbly crust.
Bake in the preheated oven for 18 to 22 minutes, or until the cheese is fully melted, the edges are golden brown and crispy, and you can see little bubbles around the sides of the dish. If you like extra color on top, you can switch the oven to broil for the last 1 to 2 minutes, watching closely so it doesn’t burn.
Remove the casserole from the oven and let it rest for about 5 minutes. This quick rest helps the cheese set just enough so you can scoop out neat portions while still keeping that rich, melty texture with chunks of pink corned beef and tubular pasta. Serve warm, straight from the glass dish.
Variations & Tips
To stay true to my grandfather’s three-ingredient spirit, I keep the base recipe to penne, white cheddar, and corned beef, but there are a few easy tweaks if you want to play without overcomplicating things. For a creamier, looser bake, stir in 1/4 to 1/2 cup of milk or cream along with the hot pasta water before baking. If you prefer a sharper flavor, use extra-sharp white cheddar or mix in a bit of Irish white cheddar for a nod to Dublin. You can swap penne for any tubular pasta you have on hand (ziti, rigatoni, or even elbows) as long as you keep the volume similar so the cheese still coats everything well. For a slightly lighter feel, use half corned beef and half cooked shredded chicken or turkey; it changes the taste but still leans on the same simple method. If you like a bit of crunch, sprinkle a small handful of crushed crackers or breadcrumbs over the top along with the last bit of cheese before baking. To meal prep, assemble the casserole up to a day in advance, cover tightly, and refrigerate—add 5 to 10 extra minutes of baking time and a splash of milk or water before it goes in the oven if it looks dry from chilling. Leftovers can be reheated in the oven at 350°F, covered with foil, until warmed through, or quickly in the microwave with a tiny splash of water to bring back the creaminess.
