Preheat the oven to 200 degrees. If making multiple omelets store the cooked omelets in the warming oven until all are ready to serve.
In a nonstick pan, heat oil over medium heat. Add the peppers, onions, and mushrooms; cook stirring frequently for approximately 2 minutes.
In a bowl, whisk the eggs with a pinch of salt and pepper. Add the eggs to the pan and cook, without stirring, until egg begins to set, approximately 1 minute. Add in the tomatoes.
In a nonstick pan on medium heat brown the sliced chicken sausage on both sides. Toast the bread.
Using a heat-resistant spatula, gently lift corner of egg; tilt pan to allow uncooked egg to flow underneath. Cook until set. Repeat the procedure until the remaining egg is cooked.
Add cheese and fold the omelet in half. Remove omelet from pan. Serve with toast, chicken sausage, and pears on the side.