Preheat oven to 350^. Spray 11x7 glass baking dish w/cooking spray. In baking dish, layer potatoes.
In medium bowl, beat eggs, cottage cheese, oregano, and garlic powder w/wire whisk until well blended. Add green peppers, mushrooms, cooked bacon, and onions (withhold a few tablespoons of the green chives to sprinkle on top after baking).
Pour egg mixture over the top of the hashbrowns. Top with shredded cheese. Bake for 30 minutes, or until knife inserted in center comes out clean. Top with the remaining chives and tomatoes, if desired. Let stand 5-10 minutes before cutting.