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.
2Tablespoonunsalted butter + additional for the pan
1/2poundYukon gold potatoes (approx. 2 medium potatoes)sliced 1/16 inch thick
Optional: pinch of red pepper flakes
1 1/2Tablespoonfresh rosemaryfinely chopped
1Tablespoonfresh thymefinely chopped
1 1/2tspkosher saltor to taste
1/4tspfreshly ground black pepperor 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.
Potatoes: if you're cutting the potatoes by hand and/or they are not thin enough, par-cook them in boiling water for 2-3 minutes before layering in the pan.