2 Tablespoons olive oil
1 small onion, diced
5 ounces fresh baby spinach
6 ounces crimini or button mushrooms, sliced
1 cup grated mozzarella cheese
1/2 cup 2 % milk
1/2 teaspoon Kosher salt
1/4 teaspoon freshly ground black pepper
Preheat the oven to 350 degrees F.
Generously spray a standard-sized muffin tin with cooking spray, making sure to cover each cup completely. Set aside.
Heat a large saute pan over medium heat. Add olive oil. When the oil begins to shimmer, add onions. Cook until softened, about 5-8 minutes.
Add the mushrooms and cook, stirring, until they shrink in size and begin to brown, about 5 minutes.
Turn the heat to low and mound the spinach on top of the mushrooms and onions. It will look like a lot of spinach, but it will wilt down. Gently stir until spinach wilts, about 2 minutes.
Set aside to cool.
Crack eggs into a medium mixing bowl. Pour in the milk. Whisk until the eggs and milk completely combine and the mixture slightly fluffy, about 1 minute. Stir in the cheese, salt and pepper.
When the spinach and mushroom mixture has cooled slightly, add it to the egg mixture and stir gently to combine.
Fill each muffin cup with 1/4 cup of egg and vegetable mixture.
Bake for 25-30 minutes or until the tops of the mini quiches begin to brown.
Remove from oven and let cool for 5 minutes. Run a butter knife around each mini quiche to free it from the muffin tin.
Serve warm or at room temperature.
Recipe found here.