Preheat the oven to 400 degrees F (204 degrees C).
In a large bowl, toss together the cauliflower, olive oil, salt, and pepper.
Arrange the cauliflower in a single layer on a large baking sheet. Roast for 25-30 minutes, until golden brown. When the cauliflower is done, leave the oven on at 400 degrees F (204 degrees C).
Meanwhile, in a large bowl, whisk the eggs.
Arrange the cauliflower at the bottom of a 9x13 baking dish.
Pour the eggs over the cauliflower. Sprinkle 1 cup cheddar over the eggs. Top with Canadian bacon, then remaining cheddar.
Bake the casserole for 18-20 minutes, until cheese is melted and eggs are cooked through.
Let the casserole cool for 10 minutes. Drizzle with hollandaise and sprinkle with chopped chives.