In an ovenproof (preferably cast-iron) skillet, on medium-high heat, add butter to melt and arrange sliced potatoes on a single layer and cook 3 minutes each side. Set aside on paper towel-lined plate to drain.
In the same skillet, cook the chorizo by crumbling it and cooking for about 10 minutes. Add onion and cook for an additional 2 minutes.
In a bowl, whisk eggs with salt and pepper and pour into skillet and lightly combine.
Arrange potatoes on top and season with chili powder. Top with Parmesan cheese.
Cook until sides are just beginning to set, 2 to 3 minutes.
Transfer skillet to oven and broil until just set in the middle and lightly golden and puffed on top, 2 to 4 minutes.
Serve warm or at room temperature. Cut into wedges. Feel free to top frittata with salsa or avocado slices.
Notes
Serve the frittata with salsa and avocado slices, a side of crusty bread with butter, and don’t forget a strong cup of joe.Optional Variations:
Dairy-Free - If you and lactose are mortal enemies, simply swap in vegan butter and either omit the cheese or use a vegan alternative.
Egg-Free - If you want a breakfast-y potato chorizo casserole without any eggs, try swapping in a liquid plant-based egg replacement instead.
Vegan - Use your favorite vegan chorizo, then follow the instructions above to make your potato chorizo bake both dairy-free and egg-free.
Extra Spicy - If fiery foods are your love language, add some extra heat! Add a chopped jalapeño with the onions, then swap in cayenne powder for up to half of the chili powder. You can also add some creamy heat by using pepper jack instead of parm.
Potato Chorizo Frittata Muffins - You can also make this frittata chorizo recipe in ready-to-grab portions by using a muffin tin sprayed liberally with non-stick spray. This is a great option for taking on a family camping trip! Assemble the mini frittatas in the prepared pan, making sure not to fill them past about ¾ of the way full. Note that since you won’t be cooking the eggs on the stovetop, you’ll want to bake them at 375F for about 15-20 minutes and forego broiling.