1Lightly grease a 3 quart casserole dish. In a large skillet over medium high heat, warm oil. Add shallots to skillet and saute' 1 minute. Add chicken strips and cook 5 minutes more or until cooked through.
Season chicken with salt, black pepper, and cayenne pepper.
2Place a layer of bread cubes in the bottom of the dish. In alternating layers, place chicken, spinach, sundried tomatoes, cheese and bread, ending with a sprinkling of bread on top.
3In a large bowl, using a whisk, combine eggs, milk, mustard, and nutmeg. Pour mixture over the casserole; cover and refrigerate 4 hours or overnight.
4Preheat oven to 350 F.
While oven heats, remove casserole from the refrigerator and warm to room temperature.
Place casserole in oven and bake 35 to 40 minutes until golden brown on top.
Remove from oven and cool 5 minutes before serving.
Serve hot or at room temperature.