Mushroom and Gruyère Croissant Breakfast Casserole

Introduction
Start your day off right with this indulgent Mushroom and Gruyère Croissant Breakfast Casserole! Combining buttery croissants, earthy mushrooms, and nutty Gruyère cheese, this casserole is the perfect balance of savory and comforting. Easy to prepare the night before, it’s perfect for a lazy weekend breakfast or a special holiday brunch.

Ingredients
4 croissants (preferably a day or two old), cut into chunks
1 cup Gruyère cheese, shredded
1 tbsp olive oil
1 cup mushrooms, sliced (button, cremini, or your choice)
1 small onion, chopped
4 large eggs
1 ½ cups milk
1 tsp Dijon mustard
Salt and pepper, to taste
¼ tsp dried thyme (optional)
Fresh parsley, chopped (for garnish)
How to Make
Step 1: Prepare the Vegetables