. Saute the onion in 1 tbsp olive oil over medium low heat until softened. Let cool.

2. In a large bowl, beat the eggs. Stir in the onion, the bacon and sausage, the cheeses and the salt and pepper.

3. Coat a 10 inch ovenproof skillet with the remaining oil. Add the egg mixture and cook over medium-low heat until the sides start to set, about 3 minutes.

4. Bake at 325F until the frittata is firm, 20 to 25 minutes.

5. Gently run a rubber spatula around the sides of the skillet to loosen and carefully flip the frittata out onto a serving plate. Cut into wedges to serve.