01 -
Grease a 23x33 cm casserole dish thoroughly to prevent sticking.
02 -
Arrange 6 bread slices at the bottom of the dish. Distribute bacon, green onions, cheddar cheese, and mushrooms evenly over the bread. Cover with the remaining 6 bread slices to form a second layer.
03 -
In a bowl, whisk together milk and beaten eggs until fully combined.
04 -
Pour the milk and egg mixture evenly over the layered bread and fillings. Cover the dish and refrigerate for at least 1 hour or up to overnight for optimal texture.
05 -
Preheat oven to 175°C. Remove cover and bake casserole for 1 hour, or until the top is golden and custard is set.
06 -
Garnish with extra green onions if desired before serving.