Preheat oven to 400 degrees.
Heat the avocado oil over the stove in a medium sized cast iron skillet. (If using a large cast iron, you may want to increase the number of eggs to 12.)
Add the minced onion and saute for about 3-5 mnutes, until tender.
Add the garlic to the onions and saute for an additional minute.
Add the sausage or ground beef to the onion mixture and cook until browned. (If meat not preseasoned, season to taste.) --I buy mine from an organic farm and the sausage is seasoned with salt, pepper, and sage.
Once the meat is cooked, add the chopped mushrooms and incorporate them well.
Add the chopped kale and make sure all of the ingredients are mixed well.
Crack all of the eggs into a medium sized mixing bowl and whisk them well. (I usually add a pinch or two of sea salt and black pepper to my egg mixture.)
Add all of the eggs to your skillet and then transfer to the preheated oven.
Bake for approx 15 minutes, until eggs are barely browned on the edges.