Pre-heat the oven to 350 degrees and butter a large sheet pan/jelly roll pan. The eggs will puff up so make sure to butter the sides too so they don't stick. If you can't have butter, avocado oil or ghee should work.
Vigorously whisk all of the ingredients in a large mixing bowl until smooth, and then pour the seasoned eggs into the buttered sheet pan.
Bake the sheet pan eggs at 350 degrees for 15 minutes. You can cut the eggs right there in the pan, or you can wait for them to cool, and scoop the egg rectangle out onto a cutting board to cut. I like to run a spatula under the eggs to be sure none of the bottom is sticking.