Preheat oven to 425 deg f.
In a bowl, combine olive oil, salt, pepper, and chives with the shredded potatoes.
Spray pie dish with oil. Spread the potatoes evenly in the pie dish making sure the walls are covered too. Pat down gently but firmly with no gaps seen.
Bake in oven for 45 minutes to an hour for golden crisp potatoes. If over browning too fast, cover with foil.
In a pan, heat 2 tbsp oil. Add sausage and onions and stir fry till lightly caramelized.
Add broccoli and mushrooms and saute on medium low heat till mushrooms are cooked.
Add garlic herb seasoning, salt and pepper to taste. Stir well and switch off flame.
To the potatoes, sprinkle about 1.5 cups of cheddar and pepper jack cheese. Add the veggies and distribute it evenly.
Whish together eggs, milk, salt and pepper till frothy.
Pour the eggs over the veggies. Sprinkle remaining cheese over the eggs.
Lower the temperature of oven to 350 deg f.
Bake for 45 minutes or until the eggs are set.
Serve with hot sauce or Sriracha sauce if preferred.