At this time the casserole can be covered and refrigerated until ready to bake. (This casserole is a great prepare ahead dish) Remove from fridge about 1 hour before serving time. Let sit to come to room temperature for about 30 minutes
Bake at 350 degrees for 30 minutes. Sprinkle with cheddar cheese and return to oven for 1-2 minutes until cheese is melted. Garnish with green onion and bacon prior to serving.