I can’t tell you how many times this dish has saved dinner at our house. You know those nights when you want something warm, cheesy, and satisfying—but also need to use up whatever’s in the fridge? That’s how this Cheesy Ham and Potato au Gratin with Peas came to be. It’s creamy, packed with layers of tender potatoes, smoky ham, and gooey cheese, and just when you think it might be too rich, the peas add a little burst of freshness.
This started as a way to use up leftover ham from the holidays, but now we make it all the time, no special occasion needed. It’s the kind of dish that fills the kitchen with that irresistible smell of bubbling cheese, making it nearly impossible to wait for it to cool before digging in. (Trust me, I’ve burned my tongue more than once.)
If you love potatoes au gratin but want something heartier, this is it. Let’s get into it.
What Makes This So Good?
✔ Great for leftovers – Perfect way to use up ham from Easter or Christmas.
✔ Comfort food at its best – Creamy, cheesy, and totally satisfying.
✔ Surprisingly simple – No fancy techniques, just good ingredients layered together.
What You’ll Need
Main Ingredients:
- 2 lbs russet potatoes – Peeled and thinly sliced (about ⅛ inch thick). If you have a mandoline, now’s the time to use it.
- 2 cups cooked ham – Diced. Use more if you like a meatier bite.
- 1 cup frozen peas – No need to cook them, just let them thaw while you prep everything else.
- 1 small onion – Finely chopped. Adds just the right depth of flavor.
- 2 tablespoons unsalted butter – For sautéing the onions.
For the Cheese Sauce:
- 2 cloves garlic – Minced. Because garlic makes everything better.
- 2 tablespoons all-purpose flour – Helps thicken the sauce.
- 1 ½ cups whole milk – You need the richness.
- 1 cup heavy cream – Because we’re not making diet food here.
- 1 teaspoon Dijon mustard – A little zing to balance the cheese.
- 1 teaspoon salt – Adjust as needed.
- ½ teaspoon black pepper – Freshly ground, if possible.
- ¼ teaspoon nutmeg (optional) – A tiny bit adds warmth and makes the cheese sauce extra special.
- 2 cups sharp cheddar cheese – Freshly shredded melts best.
- 1 cup Gruyère or Swiss cheese – Optional, but adds a nutty depth.
- ½ cup grated Parmesan cheese – For that crispy golden top.
Step-by-Step Instructions
1. Get Everything Ready
Preheat your oven to 375°F (190°C). Butter a 9×13-inch baking dish so nothing sticks. (source: Ineskohl.info)
Now, let’s talk potatoes. The thinner you slice them, the better they cook. I use a mandoline slicer for perfectly even slices, but if you’re using a knife, just try to keep them uniform. They don’t need to be paper-thin, but the closer in size, the better.
2. Make the Cheese Sauce
Melt the butter in a medium saucepan over medium heat. Add the onions and cook for about 3 minutes, until soft. Stir in the garlic and cook for another 30 seconds—just until fragrant.
Now, whisk in the flour and cook for 1 minute, stirring constantly. This part is key. If you don’t cook the flour long enough, you’ll taste it in the sauce, and no one wants that.
Slowly pour in the milk and heavy cream, whisking as you go. It’ll start off looking thin, but after a few minutes, it thickens up into a rich, creamy sauce. Stir in the Dijon mustard, salt, pepper, and nutmeg.
Now, the best part: cheese! Remove the pan from heat and stir in 1 ½ cups of cheddar and all of the Gruyère. Stir until smooth. It might feel a little thick, but that’s okay—the potatoes will soak up some of it as they bake.
3. Assemble the Layers
Spread a thin layer of cheese sauce at the bottom of your baking dish. Now, start layering:
- Half the potatoes, slightly overlapping.
- Half the ham and peas.
- Pour over half the cheese sauce.
Repeat the layers, finishing with the remaining cheese sauce. Sprinkle the remaining ½ cup of cheddar and all the Parmesan over the top.
4. Bake Until Golden and Bubbly
Cover with foil and bake for 45 minutes. Then, remove the foil and bake another 20-25 minutes, until the top is beautifully golden and bubbly.
For extra crispiness, switch to broil for 2-3 minutes at the end—just watch it closely!
5. Let It Rest (Even Though It’s Hard)
As tempting as it is to dig right in, let it rest for 10-15 minutes. This helps the layers set, so when you slice into it, you get those beautiful stacks instead of a cheesy mess.
Helpful Tips
- Shred your own cheese – Pre-shredded cheese has anti-caking agents that mess with the sauce’s texture.
- Resting time is key – If you cut into it too soon, the sauce won’t have time to thicken properly.
- Want to make it ahead? – Assemble everything up to a day in advance, cover, and refrigerate. When ready to bake, add an extra 10 minutes to the cooking time.
- For extra crispy topping – Sprinkle a little extra Parmesan during the last 10 minutes of baking.
What to Serve with This
This dish is rich, so I like to serve it with a simple green salad, steamed green beans, or even just a side of buttery dinner rolls. If it’s a holiday meal, it pairs beautifully with roast chicken, turkey, or a honey-glazed ham.
Storing & Reheating
Got leftovers? Lucky you!
- Fridge: Store in an airtight container for up to 4 days.
- Reheat: Warm in a 350°F oven for about 15 minutes, or microwave in short bursts. If it thickens too much, a splash of milk helps.
- Freeze: You can freeze it for up to 3 months—just thaw overnight before reheating.
Final Thoughts
This Cheesy Ham and Potato au Gratin with Peas is one of those dishes that just makes sense—simple ingredients, easy to put together, and packed with cozy flavors. Whether you’re making it with holiday leftovers or just craving something warm and cheesy, it’s a guaranteed crowd-pleaser.
If you give it a try, I’d love to hear how it turned out! Let me know in the comments below. Happy cooking! 😊
