Mushroom and Potato Frittata
1⁄2 cup plus 2 tbsp. olive oil (preferably Spanish)
6 cloves garlic, finely chopped
1 large russet potato (about 3⁄4 lb.), peeled
and thinly sliced crosswise
1 medium yellow onion, thinly sliced
Kosher salt and freshly ground black pepper,
1⁄4 lb. cremini mushrooms, thickly sliced
1⁄4 lb. oyster mushrooms, roughly chopped
1⁄4 cup chopped flat-leaf parsley leaves
6 eggs, beaten
1. Heat 1⁄2 cup oil in a 10" nonstick skillet over medium heat. Add garlic, potatoes, onions, and salt and pepper; cook, stirring, until softened, 13–15 minutes. Using a slotted spoon, transfer potato mixture to a bowl, leaving oil in skillet. Increase heat to medium-high and add mushrooms and salt and pepper; cook until softened, 5–6 minutes. Transfer mushrooms to the potato mixture; let cool. Set skillet aside.
2. Combine parsley, eggs, and salt and pepper in a large bowl. Add cooled onion–mushroom mixture; stir. Set aside for 10 minutes. Heat 1 tbsp. oil in reserved skillet over medium heat. Add egg mixture; cook, shaking skillet occasionally, until bottom is deep golden brown (peek carefully, using a spatula) and center is somewhat set, 6–8 minutes. Place an upside-down plate over skillet; invert tortilla onto plate. Return skillet to heat; add remaining oil. Slide tortilla into skillet, cooked side up, and cook, shaking occasionally, until deep golden brown and just cooked through, 3–4 minutes more. Slide tortilla onto a plate. Serve at room temperature, cut into wedges.