Wash & peel potatoes, cook in microwave (whole) until tender (approx. 5 min). Meanwhile, fry bacon in a medium skillet till crispy. Remove bacon on a paper towel to drain. Crumble when cooled. Cut potatoes in small chunks, add to bacon drippings in pan, and add seasonings.
Simmer potatoes while you whip up the eggs in a bowl until foamy. Pour eggs on top of potatoes, salt & pepper as desired. Cover & cook on low for 30-40 min.
Meanwhile cook mushrooms, tomato & onion in butter in a separate pan until soft, remove from heat. When egg in set up (cooked), sprinkle mushrooms & onions on top them evenly, then add crumbled bacon, then the cheese. Cover & cook on low till cheese in melted - 10 min.