Begin by greasing a 13×9 inch casserole dish using butter or nonstick spray.

Layer half of the bagel cubes at the bottom, followed by half of the crispy bacon, Gruyere cheese, and cream cheese. Repeat the layering again.

In a separate bowl, whisk together the eggs, heavy cream, salt, and pepper until smooth.

Pour the egg mixture over the layered ingredients and press down lightly on the bagels.

Cover the casserole tightly and refrigerate for at least 4 hours, ideally overnight.

Preheat the oven to 350°F and bake covered for 40 minutes, then uncover and bake for an additional 15 minutes.

Allow the casserole to cool for about 10 minutes, garnish with chives, slice, and serve.