Step 1

Preheat the oven to 350 degrees F. Spread the halved croissants, cut side up, on a parchment lined half sheet pan and toast in the oven until golden, 10-12 minutes, checking often so they don't burn. Let the croissants cool.

Step 2

Tear the croissants into large bite-size pieces and place evenly in the bottom of a 9X13-inch baking dish.

Step 3

In a 10- or 12-inch skillet set over medium heat, cook the bacon until crisp. Remove the bacon with a slotted spoon to a paper-towel lined plate. Drain all but 1 tablespoon of the bacon grease and return the skillet to medium heat.

Step 4

Add the shallot (or red onion) and a pinch of salt and pepper, and cook for 3-5 minutes, until translucent.

Step 5

Sprinkle the cooked bacon and onions over the torn croissants followed by the shredded cheese. At this point, you can lightly toss the ingredients together to distribute the cheese/bacon/onion throughout or leave as is (I usually don't toss).

Step 6

In a medium bowl, whisk together the eggs, milk, heavy cream, salt and pepper until very well-combined. Pour the egg mixture evenly over the casserole.

Step 7

Cover the baking dish and refrigerate for at least 4 hours or up to 12 hours (any longer than 12 hours and the croissants can start to break down and disintegrate).

Step 8

When ready to bake, preheat the oven to 350 degrees F. Remove the cover from the casserole and place the baking dish on a foil-lined sheet pan (to catch any spillovers). Bake for 45-50 minutes until the casserole is golden, puffy, and firm to the touch. Let stand 10-15 minutes before serving.