Add the olive oil to a large skillet on the stove over medium high heat.
Add the onions and saute for 5 minutes.
Add the breakfast sausage to the skillet, crumble and cook for 8-10 minutes.
Remove the onions & sausage from the heat and set aside.
In a large mixing bowl, whisk the eggs, milk, salt, pepper and hot sauce together.
Stir in the diced green chilies, 1 cup of the shredded cheddar cheese and the cooked sausage and onion.
Spray an 8" x 10" baking dish with cooking spray.
Pour the egg mixture into the baking dish.
Arrange the tater tots in an even layer on top.
Place in the oven to bake uncovered for 50 minutes.
Remove from the oven and sprinkle with the remaining cup of shredded cheddar cheese.
Place back in the oven for 10 minutes.
Remove from the oven and serve immediately.
Gluten Free: this recipe is gluten free. Always double-check the label on the tater tots and sausage to make sure they're gluten free.
Vegetarian: to make this recipe vegetarian, saute 2 cups of vegetables with the onions and omit the sausage. I recommend diced bell peppers, sliced mushrooms and/or spinach. You can also substitute soy chorizo for the sausage and cook the same as you would the sausage.
Make Ahead: this casserole can be made up to 12 hours in advance, covered and stored in the refrigerator until ready to bake.