1) Whisk eggs and put to side.
2) Heat oil and butter over medium heat and add the onion, green pepper, and sliced mushrooms. Cook until soft.
3) Add diced potatoes, breakfast meat, eggs, salt, and pepper.
4) Gently stir and cook until eggs are firm and moist, not dry or drippy.
5) Add cheese. Cover pan until melted.
6) Serve with hot buttered toast.