Grease a 4 quart slow cooker with shortening or spray with non-stick cooking spray to prevent sticking and make clean up easier.
I chopped stems off of broccoli, chopped onions and shredded cheese.
Prep your ingredients by chopping off the stems off of the broccoli so that you just have florets, chop the onion, mince the garlic and shred the cheeses.
Crack the eggs into a medium mixing bowl and add the milk and spices to the eggs and mix well with a whisk.
Add the onions, minced garlic, broccoli florets and Parmesan cheese to the egg mixture and stir to combine.
Cover and cook on HIGH for 1 1/2 to 2 hours. Watch this recipe carefully as some slow cookers cook hotter than others and eggs cook quickly in the slow cooker. Remember the very edge is going to get brown, but you are going to cut that off if you want. If the dish is cooking too hot you can turn the temperature down to LOW.
When it is ready, take a long sharp knife and cut along the very edge of the crock to cut the brown part off. Cut into quarters. Sprinkle cheddar cheese on the omelet and cover for a few minutes for the cheese to melt.
Carefully remove each wedge from the crock. I used a flexible pancake spatula. I then placed the omelet on a pie plate (regular plate would work fine) and added extra cheese, tomatoes, green onion and anything else you wish to garnish with.