Preheat oven to 425 degrees. Lightly beat together 2 eggs with some salt and pepper, then stir in the hash browns. Do your best to mix everything together. The hash browns will not be completely coated, but it will help hold them together.
Add 2 tablespoons of oil to a 12-inch skillet, a standard cast iron skillet, or cast iron pizza pan. Pour the hash brown mixture into the skillet.
Place in the oven and bake for 30 to 35 minutes, until crispy and the potatoes are tender.
Heat 1 tablespoon of oil in a non-stick skillet over medium heat, and sauté the zucchini, onions, and peppers, stirring occasionally until golden, about 8 minutes. Stir in the garlic, and remove from heat. Set aside.
Beat the remaining 7 eggs, salt and pepper together in the large bowl. Gently stir in the sautéed vegetables.
Remove the hash brown crust from the oven and very carefully pour the egg and vegetable mixture evenly over the crust, then spread vegetables out over the crust.
Next, sprinkle the cooked sausage over the the top. Return skillet to the oven for 10 minutes.
Remove from oven and sprinkle with the shredded cheese. Return pan to oven and bake for 3 to 5 minutes, until cheese is melted and bubbly.
Slice and serve while warm. Garnish with chopped parsley, chives or cilantro.