Step 1

Preheat oven to 375 degrees, and spray a 9x13 baking dish with non-stick cooking spray.

Step 2

Heat the oil in a large non-stick frying pan. Add all the spinach and stir until just wilted, about 2 minutes.

Step 3

Transfer the spinach to the casserole dish, spreading out so that the bottom is covered.

Step 4

Sprinkle the onions evenly out over the spinach, followed by the shredded cheese.

Step 5

Salt and pepper the eggs, to taste.

Step 6

Pour the eggs out over the spinach, cheese, and onions.

Step 7

Using a butter knife, give it a quick swirl around the pan to help the eggs settle and ingredients combine.

Step 8

Bake about 35 minutes or until the mixture is completely set and starting to slightly brown.

Step 9

Let cool about 5 minutes before cutting and serving to allow everything to settle.