Potatoes au gratin with ham is a cheesy potato casserole layered with diced ham. It's the perfect main course for your next family meal or for using up that leftover holiday ham!
Potatoes au gratin with ham makes an amazingly hearty comfort food meal. It's filled with thin sliced potatoes, a homemade cream sauce, cheddar cheese, and diced ham.
Serve potatoes au gratin at your next family dinner, like Easter, Christmas, or Thanksgiving. This recipe is easy to double or half, and can be made ahead and reheated the next day.
Ingredients and substitutions
- Potatoes - I recommend yukon gold (shown in the photos) or russet potatoes for this recipe. Both have a high enough starch content to hold their shape after baking and are widely available year round.
- Unsalted butter - If using salted butter, reduce the salt listed by ¼ teaspoon.
- Onion and garlic - Enhance the flavor of your potatoes au gratin. I don't recommend omitting either. Use fresh minced garlic for best flavor. Pre-minced garlic in a jar often has a much harsher flavor than fresh garlic.
- Flour - Flour and butter are necessary to make a roux, which thickens the cream sauce.
- Broth - Chicken broth adds flavor to your cream sauce. Vegetable or pork broth would work as a substitute, but will alter the flavor slightly.
- Milk - Whole milk makes your sauce thick and creamy. If substituting with a lower fat milk, like 1% or skim, your sauce will turn out thinner.
- Seasoning - Salt, pepper, and thyme add flavor to your sauce. Test your ham before seasoning your sauce. If your ham is very salty, you may want to reduce the amount of salt slightly. I've already reduced the salt by half to account for the saltiness of ham (compared to my plain potatoes au gratin recipe), but feel free to season to taste.
- Sharp cheddar cheese - I highly recommend grating your cheese fresh from a block. Pre-grated bagged cheeses are coated in anti-clumping powders that can get grainy when melted.
- Ham - Any cooked/cured/smoked ham works in this recipe. Cubed ham steak, leftover spiral sliced ham, or thick cut deli ham are great options.
How to thinly slice potatoes
My secret for evenly sliced potatoes? Use a mandoline slicer, like this version on Amazon.
The best part about using a mandoline slicer is that you can set it to slice your potatoes at ⅛" and every slice comes out perfectly. This is important because your potatoes will all cook at the same rate in the oven.
If you don't have a mandoline, don't fret! Do you have a food processor? It may have come with a slicing attachment. Or, check the sides of your box cheese grater - one side may have a vegetable slicer.
If all else fails, carefully slice your potatoes using a chef's knife. This option is the most time consuming but gets the job done.
Potatoes au gratin can be assembled a day ahead and stored in the refrigerator overnight before baking. Cover your casserole dish with plastic wrap, pressing down to keep out as much air as possible. Exposed potatoes may discolor slightly overnight.
While your oven is preheating, bring your casserole to room temperature on the counter top, then bake as directed in the recipe card.
Your casserole can also be baked, cooled, and stored in the refrigerator overnight. To reheat an entire baked casserole, preheat your oven to 350 degrees Fahrenheit while your casserole comes to room temperature on the counter top. Cover and bake for 30 minutes, or until heated through in the center.
What to serve with ham and au gratin potatoes
Potatoes au gratin with ham is a hearty main course that pairs well with a lighter side dish, like a side salad or roasted veggies. Here are a few of my favorite side dishes:
- Lemon parmesan asparagus
- Strawberry spinach salad
- Kale apple slaw
- Parmesan brussels sprouts
- Winter fruit salad
- Roasted zucchini and squash
Potatoes Au Gratin with Ham
- 2.5 pounds (1134 g) yukon gold potatoes, or russet potatoes
- 1 small onion, diced
- 4 cloves garlic, minced
- ¼ cup (56 g) unsalted butter
- ¼ cup (30 g) all-purpose flour
- 8 ounces (227 g) chicken broth
- 16 ounces (454 g) milk
- ¾ teaspoon salt
- ¾ teaspoon pepper
- ½ teaspoon dried thyme
- 2 cups (226 g) freshly shredded sharp cheddar cheese
- 12 ounces (340 g) cooked ham, chopped
- Preheat oven to 350 degrees Fahrenheit. Lightly grease a 9x13 casserole dish and set aside.
- Scrub and rinse potatoes, optionally peel (if desired), and slice to ⅛" thickness. I recommend using a mandoline slicer if you have one available. Set aside.
- In a saucepan over medium heat, add butter. Once melted, add onions and cook until they begin to brown and turn translucent, about 4-5 minutes. Add garlic and cook an additional 30 seconds. Add flour and stir to coat and create a paste. Cook for one minute.
- Whisk in broth and milk. Continue whisking until no lumps remain. Cook sauce for another 3-4 minutes, or until thickened slightly. Remove from heat. Add salt, pepper, and thyme, stirring to incorporate.
- In prepared 9x13 pan, arrange ¼ of sliced potatoes in the bottom of the dish, overlapping slightly. Top with ⅓ of your chopped ham. Pour ¼ of sauce over ham. Repeat once more, adding another layer each of potatoes, ham, and sauce. Next, add half of the shredded cheddar cheese in an even layer. Add two more layers of potatoes, ham, and sauce (for a total of four layers each of potato, ham, and sauce), and top with remaining shredded cheese.
- Cover casserole with foil and bake for 45 minutes. Uncover and bake an additional 15-20 minutes, or until potatoes can easily be pierced through with a fork in the center of the casserole. The thicker your potatoes are sliced, the longer it will take for them to cook through.
- Optionally, turn on broiler for 2-3 minutes to lightly brown cheese on top before serving.
- If your ham is very salty, you may want to reduce the listed salt slightly.
- I recommend freshly shredding cheese from a block instead of using pre-shredded bagged cheese, which is often coated in an anti-clumping powder that becomes grainy when melted.
- Leftover casserole will keep for up to 4 days in a sealed container in the refrigerator.
- Casserole can be assembled ahead and stored in the refrigerator overnight before baking. Cover potatoes with plastic wrap, pressing down to keep out as much air as possible. Exposed potatoes may discolor slightly overnight. While oven is preheating, bring casserole to room temperature on the counter top, then bake as directed above.
- Casserole can be baked, cooled, and stored in the refrigerator overnight. To reheat entire baked casserole, bake, covered, at 350 degrees for 30 minutes, or until heated through in the middle.