Bacon and Cheese Frittata

5 slices bacon
2 tablespoons extra-virgin olive oil
1 medium onion, finely chopped
8 large eggs
1/4 teaspoon salt
1/8 teaspoon pepper
couple slices of American cheese, broken into pieces

Preheat the oven to 325 degrees F.
In a large skillet, cook the bacon over medium heat, flipping once, until cooked but not crisp
Drain on a paper towel, then chop into bite-size pieces.
Pour off the bacon fat and add 1 tablespoon of the olive oil to the skillet.
Add the onion and cook over medium-low heat until softened, about 7 minutes.
Let cool.
In a large bowl, beat the eggs. Add the onion, the bacon, the cheeses and the salt and pepper and stir gently.
In a 9- or 10- inch ovenproof skillet, heat the remaining tablespoon of olive oil (swirl the oil to coat the bottom and sides of the skillet).
Add the egg mixture and cook over medium-low heat until the sides start to set, about 3 minutes.
Bake in the oven until the frittata is firm, 20 to 25 minutes.
Gently run a rubber spatula around the sides of the skillet to loosen the frittata.
Place a serving plate over the skillet and carefully flip the pan to release the frittata