Potato Egg Casserole is an easy, elegant, frittata-like dish to serve at breakfast or brunch. Layers of gruyere cheese, herbs, garlic, and shallot burst with flavor in this vegetarian egg bake. Top with arugula for added texture, color, and bright, peppery freshness.
You should probably go ahead and block out Saturday morning, making sure it’s free of any plans (ha, #2020) because you’ve got a date with a hot cup of coffee, a puzzle, and a slice – or two – of this easy egg bake.
Then you’re going to want to have another slice for lunch because there’s arugula here and it’s basically a salad and brunch all rolled into one. Making dreams come true.
And then there’s breakfast-for-dinner because you can’t get enough of gruyere cheese combined with warm herbs and life is just SO DANG DELICIOUS RIGHT NOW.
Before we get too carried away, let’s take a look at just how easy it really is, with a few steps and minimal ingredients, you’ll be a brunch Queen in no time (as if you already aren’t, my bad).
Speaking of Ingredients…
Simplicity at its finest. The best of aromatics and herbs, coming together to create a flavorful medley that’s anything but basic.
There’s yellow onion and shallot, and of course, you cannot forget the garlic (never!) and maybe a pinch of red pepper flakes because I always like to add a pinch for good measure.
There are fresh herbs: rosemary and thyme. Oh me, oh my, these herbs are my FAVORITE for savory, cozy, winter recipes!
Naturally, there are eggs for the custardy egg base, along with half-and-half for the velvety texture.
We can’t forget the potatoes. This recipe uses Yukon Gold potatoes for their creaminess. Use a mandoline to thinly slice the potatoes. In order for them to cook through, they must be thin. Alternatively, if you need to cut them by hand I’d recommend par-cooking them in boiling water for 2-3 minutes before layering them in the casserole.
Then there’s the cheese. Oh you know we cannot, will not, have an egg casserole without CHEESE. Gruyere is the main star here, but you know we couldn’t complete it without a little parmesan too.
How to Make It
The base of flavor starts by sauteeing yellow onion and shallot in butter. The fat from the butter adds richness to the onion, and adding in a shallot brings more depth of flavor, with a slight sweetness. Perfection.
Also sautéed is the garlic, red pepper flakes (if using) and the herbs. All the flavors meld together so, so beautifully and will be incorporated throughout the casserole.
In another bowl, you’ll combine the eggs, half-and-half, and salt and pepper. Whisk, whisk, whisk until combined and fluffy-ish. Once the sauteed mixture has cooled slightly, you’ll stir it into the eggs.
Next, layer the thinly sliced potatoes in the tart or pie pan (or an 8×8 glass baking dish will work, too). If you’re concerned your potatoes aren’t thin enough – we’re looking for about 1/16 of an inch – then I’d recommend par boiling them for 2-3 minutes before layering to ensure they’ll cook through.
I’ll say it again: using a mandoline really helps this process of making the thin slices, and in turn that will eliminate the extra step of boiling!
Once the potatoes are layered, evenly spread about 2/3rds of the cheese across the top, reserving the rest for the very very top of the casserole.
Then, pour the egg mixture on top of the potatoes. You may need to go slowly as it finds its way around the potato slices. Top with the remaining cheese and bake away!
Once the edges are golden brown and the center is set, your egg bake is ready to enjoy!
Let it cool for at least 15 minutes before serving so it has time to set up and you can get those perfect slices out.
I love topping it with fresh arugula for added freshness and texture. .
If you’re a bacon lover, that would work too. That saltiness combined with the warm, eggy, casserole? That would be a win.
More Breakfast Recipes to Love:
- Kale, Shallot, Goat Cheese Quiche
- Mediterranean Quiche
- Ricotta, Asparagus, Pesto Quiche
- Mediterranean Frittata
Potato Egg Casserole with Gruyere and Herbs
- 2 TBSP unsalted butter + additional for the pan
- 1/2 cup yellow onion diced
- 1/2 cup shallot diced
- 1/2 pound Yukon gold potatoes (approx. 2 medium potatoes) sliced 1/16 inch thick
- 3-4 garlic cloves minced
- Optional: pinch of red pepper flakes
- 1 1/2 TBSP fresh rosemary finely chopped
- 1 TBSP fresh thyme finely chopped
- 6 eggs
- 1/4 cup half-and-half
- 3 oz. gruyere cheese shredded
- 1/4 cup parmesan cheese shredded
- 1 1/2 tsp kosher salt or to taste
- 1/4 tsp freshly ground black pepper or to taste
- Spread approximately ½ TBSP butter on the sides and bottom of a 9-inch tart or pie pan with sides (or an 8x8 glass baking dish). Preheat the oven to 350F.
- In a skillet over medium heat, melt butter and add the diced onion and shallot, with a pinch of salt to begin layering the flavors. Cook for 2-3 minutes, then add the chopped garlic, red pepper flakes if using, rosemary, and thyme. I like to add a pinch of red pepper flakes here, too. Cook for an additional 2-3 minutes until tender and fragrant. Remove and let cool slightly.
- Meanwhile, whisk together the eggs, half-and-half, ½ tsp kosher salt, and ¼ tsp black pepper (more or less as desired). Set aside.
- In the prepared baking dish, layer the very thinly sliced potatoes in an even layer on the bottom, creating a second layer as needed and continuing to layer until you've used all the potato slices. Evenly spread ⅔ of the cheese on top of the potatoes. Reserve the rest of the cheese for the top.
- Pour the cooled onion mixture into the whisked eggs and carefully pour the eggs on top of the cheese and potatoes, allowing it to soak down into the potato layers. Place the baking dish on top of a baking sheet if there’s a risk for any liquid to spill out.
- Bake for 36-40 minutes, until the edges are golden brown and the center is just set. Let cool for 15-20 minutes before serving. Top or serve with arugula for a bright and peppery flavor combination.