Preheat oven to 400 degrees.
Whisk the eggs together in a large bowl with the salt and pepper, set aside.
In a 12 inch nonstick pan with oven proof handle, add olive oil and swirl around bottom of pan and up the sides so eggs will release when cooked.
Brown potatoes and onions together over medium heat for about 8 minutes.
Once potatoes and onions are cooked, layer in bottom of pan to form the "crust." Turn off stove.
Put sausage on top of potatoes and onions. Put cheese on top of sausage.
Pour egg mixture over everything.
Sprinkle chives on top.
Bake in preheated oven for 15 minutes, or until eggs are almost set. Eggs will continue to cook when you take them out of the oven. Do not overcook or Frittata will dry out.
Cool to room temperature and invert onto plate and then invert again onto serving platter. Cut into wedges and enjoy.