Butter a 9" X 13" Pan.
Line pan with diced bread.
Cover with cheddar and chives.
Whisk together eggs, dijon, half & half, salt and pepper.
Pour over Bread.
Ideally, refrigerate overnight.
Bake in the oven at 350°F until golden brown and puffed up (approx. 1 hour).
Let sit for 10 minutes to set before slicing.