Essentially a crustless quiche or open-face omelet, frittata is easier than yet as versatile as either dish. When I first learned to make frittata, I was taught to use four core ingredients: eggs, onion, potato and cheese. From there, you can go beyond the basic filling to match the season or contents of your fridge. Replace some of the onion and potato with asparagus and spinach, eggplant and summer squash, or carrots and chard, choosing a complementary cheese. Mushrooms, arugula, tomatoes and herbs can also be swapped in or served on top for an even fuller portion.
A basic ratio makes almost any combination work. For a 10-inch skillet, use six eggs, 3 tablespoons of sour cream or other full-fat dairy and 3 cups of other ingredients in a blend of vegetables, meat and cheese. Precook everything, either overloading the pan as I do here (and turning often) or in batches, before you add the eggs. I get the most consistent results if I start the eggs on the stovetop and then slide the pan in the oven. The broiler also browns surface cheese if you like a crunchy topping.
Golden Onion and Potato Frittata
Serves 3-4
3 tablespoons olive oil
3/4 cup thinly sliced onion
2 cups thinly sliced potatoes
2 cloves garlic, minced
6 eggs
3 tablespoons sour cream
Sea salt and freshly ground black pepper to taste
1/4 cup grated Parmesan cheese, plus more for topping
In a 10-inch, ovenproof cast iron or nonstick skillet, heat the oil over medium heat. Add the onion and potatoes and sauté for about 10 minutes, until the onions soften. Add the garlic and cook for about five minutes, until the potatoes are tender and the onions are golden. Throughout the cooking time, use a wooden spatula to turn the vegetables regularly and ensure even cooking; if they start to stick to the pan, add another tablespoon of oil.
In a medium bowl, whisk the eggs with the sour cream, salt and pepper; fold in the cheese. Pour the egg mixture over the vegetables. Use the spatula to stir to the skillet’s bottom as you continue cooking for about two minutes, just until the eggs start to form large, wet curds. Use the spatula to distribute the pan’s contents evenly and then cook, undisturbed, for another 30 seconds.
Sprinkle the frittata with cheese, if desired. Set the broiler to low, and use potholders to place the skillet under it on the oven’s top rack. Cook for three to four minutes, watching closely, until the surface turns puffy and lightly browned. Use the potholders to pull the hot skillet from the oven.
Let the frittata rest for five minutes to finish cooking, and then use a thin spatula to loosen the edges. Slice wedges, taking care not to score the pan, and lift each free. Serve immediately or at room temperature, storing leftovers in a sealed container in the fridge.
Julie Laing is a Bigfork-based cookbook author and food blogger at TwiceAsTasty.com.