The Kitchn: This cheesy spinach frittata will never let you down
Serves 4 to 6
1 medium shallot
3 ounces sharp cheddar cheese
1/2 ounce Parmesan cheese
8 large eggs
1/3 cup whole or 2% milk
1/2 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
2 tablespoons olive oil
5 ounces baby spinach (about 5 packed cups)
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