Ham and Potato Au Gratin

What’s This All About?

Let me tell you about my go-to comfort food that never fails to impress. This Ham and Potato Au Gratin is what happens when thinly sliced potatoes meet smoky ham chunks, get bathed in a creamy garlic-infused sauce, and then buried under a mountain of bubbly cheese. It’s basically what would happen if a baked potato and ham had a beautiful French-inspired baby. This dish has saved many family dinners and potlucks, and the best part? It looks fancy but is actually pretty simple to throw together.

Why You’ll Love This Recipe

• It’s that perfect combo of fancy-looking but actually pretty straightforward.
• The leftovers taste EVEN BETTER the next day (if there are any).
• You can prep it ahead of time and just pop it in the oven when you’re ready.
• It’s customizable – add more veggies, swap cheeses, make it your own!
• The crispy edges are basically edible gold and worth fighting over.
• It’s hearty enough to be a main dish with a simple salad on the side.
• People will think you spent way more time on it than you actually did.

The Good Stuff You’ll Need

For the Potatoes and Ham:

• 2½ pounds russet potatoes (about 5-6 medium spuds – the starchy kind work best)
• 1½ cups diced ham (leftovers from Easter or Christmas are PERFECT, or just grab some from the deli counter)
• 1 medium onion, thinly sliced (yellow or white, doesn’t matter)
• 2 cloves garlic, minced (or more, I won’t judge)
• 2 tablespoons butter (the real stuff, not that fake margarine nonsense)
• Salt and pepper to taste (be generous here!)
• 1 teaspoon fresh thyme leaves (dried works too, use about ½ teaspoon)

For the Creamy Sauce:

• 2 tablespoons butter
• 2 tablespoons all-purpose flour
• 2 cups whole milk (2% works in a pinch, but come on, live a little)
• 1 cup heavy cream (I said we’re not dieting today!)
• 1 teaspoon Dijon mustard (secret ingredient that makes everything pop)
• ¼ teaspoon nutmeg (fresh grated is amazing but the pre-ground stuff is fine)
• 1 bay leaf (optional but adds a subtle something-something)
• Salt and freshly ground black pepper

For the Cheesy Topping:

• 2 cups grated Gruyère cheese (or Swiss if Gruyère is being all fancy and expensive)
• 1 cup grated sharp cheddar (for that perfect color and tang)
• ¼ cup grated Parmesan (the real stuff, not the sawdust in a green can)
• ¼ cup panko breadcrumbs (for that extra crispy top)
• 1 tablespoon olive oil or melted butter

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Let’s Do This Thing

Prep Work (20 minutes):

1. Preheat your oven to 375°F (190°C). Grab a 9×13 baking dish and give it a light coating of butter or cooking spray.
2. Peel those potatoes (or don’t if you’re feeling rustic and like potato skin). Slice them THIN – like ⅛-inch thin. A mandoline is your best friend here, but a sharp knife works if you’ve got decent knife skills and patience. Drop the slices in cold water as you go to prevent browning.
3. In a skillet over medium heat, melt 2 tablespoons of butter. Toss in those onion slices and cook until they’re soft and starting to get some color, about 5-7 minutes. Add the garlic, cook for another minute until fragrant. Set aside.

Make the Sauce (10 minutes):

4. In a medium saucepan over medium heat, melt the 2 tablespoons of butter. Sprinkle in the flour and whisk constantly for about 1-2 minutes until it smells slightly nutty (but not burned!).
5. Gradually pour in the milk and cream, whisking constantly to avoid lumps (nobody wants flour lumps). Add the bay leaf if using.
6. Keep whisking occasionally as the sauce thickens, about 5 minutes. Once it can coat the back of a spoon, stir in the Dijon, nutmeg, salt, and pepper. Remove the bay leaf and turn off the heat.

Assembly (15 minutes):

7. Drain those potato slices and pat them dry with paper towels or a clean kitchen towel.
8. Create layers in your baking dish:
   • Start with a thin layer of sauce on the bottom
   • Add a layer of overlapping potato slices
   • Scatter some ham pieces and a bit of the cooked onion-garlic mixture
   • Sprinkle with a bit of the cheese mixture and some thyme
   • Pour over some sauce
   • Repeat these layers until you run out of ingredients, finishing with sauce and reserving about 1 cup of cheese for the final topping
9. In a small bowl, mix the remaining cheese with the panko and drizzle with olive oil or melted butter. Toss with your fingers until combined.
10. Sprinkle this cheesy breadcrumb mixture all over the top layer.

Bake Time (1 hour):

11. Cover the dish with foil (not too tight – you don’t want it touching the cheese).
12. Bake for 45 minutes covered.
13. Remove the foil and bake for another 15-20 minutes until the top is golden and bubbly and the potatoes are fork-tender.
14. Here’s the hardest part: Let it rest for at least 15 minutes before serving. I know it’s torture, but it needs time to set up and for the flavors to calm down a bit.

Serving Suggestions

• Pair with a crisp green salad with a tangy vinaigrette to cut through the richness.
• A glass of dry white wine (think Chardonnay or Sauvignon Blanc) makes this meal feel extra special.
• Some steamed green beans or asparagus on the side add color and a bit of virtue to balance out all that cheesy goodness.
• Crusty bread is never a bad idea, despite the carb-on-carb crime. You’ll want it to soak up any sauce left on your plate.
• For a brunch situation, serve with some fruit and mimosas.

Switch It Up

Got the basic idea but want to make it your own? Try these twists:

• Smoky Version: Add a teaspoon of smoked paprika to the sauce and use smoked gouda for part of the cheese.
• Veggie Loaded: Add layers of sautéed mushrooms, bell peppers, or spinach for more nutrition and flavor.
• Bacon Lover’s: Replace some of the ham with crispy bacon pieces, or top with bacon before the final cheese layer.
• Leek Edition: Replace the onion with 2 cleaned and sliced leeks for a more delicate flavor.
• Herb Garden: Add fresh chopped herbs between layers – rosemary, sage, or tarragon all work wonderfully.
• Spicy Kick: Add some red pepper flakes or diced jalapeños to the onion mixture if you like heat.

Leftovers & Make-Ahead Tips

• This actually tastes BETTER the next day. Store covered in the fridge for up to 3 days.
• To reheat: Cover with foil and warm in a 350°F oven for about 20 minutes, or microwave individual portions (though the microwave makes the top less crispy).
• To make ahead: Assemble completely, but don’t bake. Cover and refrigerate for up to 24 hours. Let it sit at room temperature for 30 minutes before baking, and you might need to add 5-10 minutes to the baking time.
• You can freeze this unbaked, but the texture of the potatoes might change slightly. If freezing, thaw completely in the refrigerator overnight before baking.

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Questions People Actually Ask

Q: Can I use pre-sliced potatoes from the store?
A: In theory, yes, but they often have preservatives that affect the flavor and texture. If you’re in a time crunch though, just rinse them well first to remove some of the added starch.

Q: My sauce looks curdled/grainy. What happened?
A: You probably added the milk too quickly or had the heat too high. Next time, make sure your milk is at room temperature and add it gradually while whisking constantly.

Q: Can I make this without ham?
A: Absolutely! It’s delicious as a plain potato gratin, or substitute with cooked chicken, turkey, or keep it vegetarian by adding more veggies.

Q: My potatoes are still crunchy even after the full baking time. Help!
A: Your slices were probably too thick. For now, cover it back up and continue baking until a fork slides easily through the potatoes. Next time, try to slice them thinner or parboil them for 5 minutes before assembling.

Q: Can I use different cheese?
A: The beauty of this dish is its flexibility! Just make sure you include at least one cheese that melts well. Good substitutes for Gruyère include Emmental, Jarlsberg, or Fontina. The cheddar can be replaced with Gouda or Colby.

Q: I don’t have heavy cream. Can I just use all milk?
A: You can, but the sauce won’t be as rich. Try adding an extra tablespoon of butter to compensate. Or use half-and-half if you have that.

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