In a non-stick pan, heat the oil over medium heat. Add the onions and mushrooms; sauté until soft. Then add the ham and saute until lightly browned.
Add the eggs into the pan. Move the eggs using circular motions with a spatula or wooden spoon to fluff up and cook, (move the pan on and off the heat as needed to prevent the eggs from overcooking or drying out). Remove the pan from the heat while the eggs are still moist. Season with pepper. Taste and add salt if needed.
Lightly toast the bagel. (Melt the cheese on also)
Portion the eggs onto the bagel. Serve with watermelon.
Notes
Pro tip: Purchase a container of precut watermelon so you don't have to purchase an entire watermelon if desired.