Spray slow cooker with a nonstick cooking spray.
Layer shredded potatoes or hash browns on the bottom of the slow cooker.
Sprinkle top of potatoes with half of shredded mozzarella cheese, parmigiano reggiano cheese, sausage links, and chopped sun-dried tomatoes. Set aside.
In a mixing bowl combine eggs, half & half, and milk; whisk until well combined.
Whisk in dried basil, garlic powder, chili powder, salt and black pepper; whisk until completely combined.
Pour egg mixture over prepared hash browns and smooth out the top.
Sprinkle the rest of the mozzarella cheese over the top.
Cover slow cooker and cook on LOW for 6 to 8 hours, OR on HIGH for 3 to 4 hours.
Garnish with green onions and tomatoes; Serve.