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.