Potato-Tomato Casserole with Gruyère
If you have a surplus of potatoes and tomatoes laying around, use them to whip up this cozy potato-tomato casserole with Gruyère.
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Layered with hearty potatoes, juicy tomatoes, and melty cheese and topped with a crunchy, garlicky panko breadcrumb crust, this potato-tomato casserole with Gruyère makes a delicious side dish or satisfying main meal. It’s also one of those recipes casual enough for a family dinner but elegant enough to serve at holiday feasts.
I love casseroles, especially because I love anything that cooks in one pan or pot. They could be a little time-consuming to prepare, but they’re usually easy to do. If you have all the tools you need, you could assemble this mini masterpiece in about 20 minutes and dig into it in just over one hour.
This recipe makes a wonderful accompaniment to steak, chicken, and even fish. It could also be the star feature served alongside a crisp salad like maybe this delicious blue cheese salad. Either way, you can’t go wrong with this comforting casserole.
Why You’ll Love This Potato-Tomato Casserole with Gruyère
- It’s a great way to use tomatoes when they’re not in peak season: Cooking tomatoes this way helps rejuvenate the off-season “love apple.”
- It has a medley of flavors and textures: Earthy potatoes, juicy tomatoes, gooey cheese, and a delightfully crunchy and garlicky topping offer an explosion of flavors and textures.
- This casserole makes a nice holiday dish: Serve as a side at Thanksgiving, Christmas, or other indulgent holidays or events.
Ingredients You’ll Need
- Panko Breadcrumbs: Don’t use regular breadcrumbs; only panko breadcrumbs are crunchy enough.
- Fresh Garlic: Lots of fresh garlic infuses the breadcrumbs.
- Pecorino Romano Cheese: I highly recommend this sharp cheese for maximum flavor.
- Extra Virgin Olive Oil: Make sure to use EVOO and not regular olive oil.
- Yellow Potatoes: You can substitute with Yukon Gold. Russets will work, too.
- Gruyère Cheese: You can substitute with Swiss, which is comparable to Gruyère.
- Vine Tomatoes: Beefsteak or Roma tomatoes are also fine to use.
- Fresh Herbs: Parsley, thyme, rosemary, or a mix of all three are good options.
See the recipe card below for more information on ingredients and quantities.
How to Make Potato-Tomato Casserole with Gruyère
- Prepare the topping: Mix together the panko, garlic, Pecorino, and olive oil in a bowl. Set aside.
- Assemble the casserole: Cut the potatoes and the tomatoes into 1/8″ thick slices. Layer the potatoes, slightly overlapping, in a casserole dish brushed with olive oil. Sprinkle them with salt and pepper. Top with some Gruyère, some more Pecorino, and 8 to 10 tomato slices. Repeat this process for a total of 3 layers.
- Top with the panko: Top the casserole with the seasoned panko breadcrumbs and drizzle them with some more olive oil.
- Cook the casserole: Bake, uncovered, for 70 minutes in a 375F oven or until the potatoes are tender and the panko topping is golden brown.
Pro Tips
Use a mandolin: You’ll save yourself a lot of time by slicing the potatoes with a mandolin. Just be sure to use one with a safety top (pretty please!).
Salt and pepper the potatoes after layering them in the dish: If you slice them with a mandolin, they may stick together and be difficult to salt properly. Layer them in the dish first, then sprinkle each layer with salt and pepper.
Cut the potatoes into ¼” inch-thick slices: Cutting them on the thinner side will yield a faster cook time.
Reheat the casserole in the oven instead of the microwave: This will ensure the topping stays crunchy.
Suggestions for Variations and Substitutions
- Use Yukon Gold potatoes if you can’t find yellow potatoes. You can also use russet potatoes.
- If you can’t find vine tomatoes, beefsteak or Roma tomatoes will work.
- If you can’t find Gruyère or want to use something less expensive, Swiss works just as well. You can also sub with creamy mozzarella or fontina for an Italian flair.
Recipe FAQs
Yes, you can assemble this casserole the day before, store it in the refrigerator, and bake it the next day. I suggest preparing the panko topping right before you cook the casserole.
Yes, you can use Swiss, which is similar to Gruyère but less expensive. Other options are Gouda, mozzarella, and fontina.
I suggest using a mandolin (with a hand guard), so you can slice the potatoes thinly, evenly, and quickly.
Storage
Refrigerator
Store in an airtight container in the refrigerator for up to 3 days.
Freezer
I don’t recommend freezing this casserole, mainly because of the tomatoes’ high water content.
Reheat
Reheat in an aluminum pan, uncovered, in the oven at 350F until warmed through and the top is nice and crispy.
More Potato Recipes
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Potato-Tomato Casserole with Gruyère
Ingredients
For the Breadcrumb Topping
- 1 cup panko breadcrumbs
- 3 garlic cloves peeled and minced
- 3 tablespoons Pecorino Romano cheese
- 3 tablespoons extra virgin olive oil
For the Casserole
- 2 tablespoons extra virgin olive oil
- 3 to 4 medium yellow potatoes unpeeled and sliced into ⅛" pieces (Note 1)
- ¾ teaspoon kosher salt divided (⅛ teaspoon for each potato and tomato layer)
- black pepper freshly ground
- 2 cups Gruyère cheese shredded and divided (Note 2)
- ½ cup Pecorino Romano cheese grated and divided
- 5 vine tomatoes sliced into ⅛" pieces (Note 3)
- Fresh herbs handful, minced (Italian flat-leaf parsley, thyme, or rosemary)
Instructions
- Preheat the oven to 375F and position a rack in the middle of it. Assemble the breadcrumb topping by mixing together the panko, minced garlic, Pecorino, and olive oil in a small bowl. If you want, you could wait to mix in the olive oil until you're ready to top the casserole with the breadcumbs. Set aside.1 cup panko breadcrumbs; 3 garlic cloves, peeled and minced; 3 tablespoons Pecorino Romano cheese; 3 tablespoons extra virgin olive oil
- For the casserole, pour the 2 tablespoons of olive oil into the bottom of a 9×13 casserole dish. Using a mandolin, slice the potatoes into approximately ⅛" thick pieces. Slice the tomatoes, also into roughly ⅛" each pieces. Layer some potato slices on the bottom of the casserole dish, overlapping as you go. Sprinkle them with ⅛ teaspoon kosher salt and some pepper, and top them with ⅓ of the Gruyere, followed by ⅓ of the Pecorino, and finally the tomato slices with another ⅛ teaspoon kosher salt. (Add about 8 to 10 tomato slices per layer.) Repeat this process for a total of 3 layers.2 tablespoons extra virgin olive oil; 3 to 4 medium yellow potatoes, unpeeled and cut into ⅛" slices; ⅛ teaspoon kosher salt; freshly ground black pepper; 2 cups Gruyère cheese, shredded and divided; ½ cup Pecorino Romano cheese, grated and divided; 5 vine tomatoes, cut into ⅛" slices; ⅛ teaspoon kosher salt
- Cover the top layer of tomatoes with the seasoned panko breadcrumbs, and drizzle them with a little extra virgin olive oil to ensure they're well-moistened so they brown instead of burn.
- Place the casserole dish, uncovered, on the center oven rack. Bake for about 70 minutes, until the potatoes are fork tender and the top is golden brown. If the top begins to turn too dark before the potatoes are done, cover it with foil to finish cooking. Let it sit for 10 to 15 minutes before cutting. Garnish the panko topping with the fresh herbs. Enjoy!Fresh herbs; handful, minced (Italian flat-leaf parsley, thyme, or rosemary)
