Slowly heat up a cast iron pan to medium low. In the meantime, mix eggs in a bowl and set side. Dice veggies to your liking. Small potato cubes (< 1/2") are easiest to brown on a pan and what I prefer.

Add oil to heated cast iron and cook eggs to your liking. I like medium low for a cast iron for scrambled eggs because it doesn't burn the eggs and it's easier to get fluffy scrambled eggs. I learned from a friend who is a chef at a breakfast restaurant that adding a small amount of milk helps you get fluffier scrambled eggs. Season to taste, I love oregano on my eggs. Set eggs aside.

Bring up heat to medium high and add oil. Add potatoes and cook all around. When the potatoes are brown ~70% of the way around add butter, garlic, onions and mushrooms. Season to taste. Stir constantly. I typically cook until the garlic gets on the darker end because it adds a bit of crunchy garlic texture in each bite that I like, but it's always up to you. Place on plate next to eggs.

Slice the avocados and place next to everything.

Garnish if desired and serve immediately. Enjoyed best next to an open window with a morning breeze, no technology, and a cup of coffee.