You can assemble the dish ahead of time and refrigerate or freeze it. Thaw overnight in the fridge before baking if frozen. Use cold milk for the béchamel to avoid lumps. Whisk continuously while adding the milk slowly to keep the béchamel smooth. Reheat in the oven at 350 degrees F until warmed through. Serve this dish with a side salad for freshness and pair it with garlic bread for added flavor. It is best enjoyed with a sprinkle of Parmesan cheese on top.