Step 1

Stuff each croissant with ham and cheese like you would if you were making a sandwich, evenly distributing the ham and cheese between the 10 croissants.

Step 2

Place them in a lightly greased 9x13-inch baking dish.

Step 3

In a large bowl whisk together eggs, heavy cream, half-and-half, Dijon mustard, salt and pepper. Pour mixture over croissants.

Step 4

Use a fork or spatula to press croissants down into liquid as much as possible. If you can't get the tops of the croissants submerged at all, spoon the liquid over them.

Step 5

Sprinkle with Parmesan cheese and green onion.

Step 6

Cover with plastic wrap and refrigerate overnight.

Step 7

Preheat oven to 350 degrees. Place baking dish in oven for 40 to 45 minutes, covering with foil after 25 minutes so the top doesn't get too brown.