Preheat oven to 350F. Grease a 9 x 13 baking dish and set aside.
Add bacon to a large skillet and cook over medium heat until nice and crispy. Add onions and cook until translucent. Remove and drain on a paper towel.
16 ounces bacon, 1 medium onion
In a large bowl, whisk together eggs, salt, pepper, and hot sauce.
8 large eggs, 1 teaspoon salt, 1 teaspoon black pepper, 1 teaspoon hot sauce
Add hash browns, shredded cheese, cottage cheese, bacon and onions.
16 ounces bacon, 1 medium onion, 4 cups frozen hash browns, 8 ounces sharp cheddar cheese, 6 ounces Swiss or Gruyere cheese, 16 ounces small curd cottage cheese
Mix until combined.
Scoop mixture into prepared baking dish and bake for 35 to 45 minutes or until center is set. Let casserole rest for 5 to 10 minutes before serving.
Top with snipped fresh chives if desired.