We are looking to do this gratin from Spike Mendelsohn and had a question for anyone who has ever used celery root in a gratin. His technique involves slicing the celery root and potatos a quarter-inch thick, then pan roasting in a single layer for about 10 minutes per batch. As we are looking to double this recipe, the amount of time needed to pan roast these veggies + baking off the gratin would be considerable.
I was wondering if this step of 'par-cooking' was necessary because if they went in raw, the layer of pear on top would overcook by the time the potato and celery root were finished? I noticed that other celery root gratin recipes that included other fruits like apples always involved a step of cooking the celery root and potato before adding it to the casserole dish(even saw one that recommended steaming the CR and potato for 5 mins.)
Never cooked with this vegetable before and would love any feedback. Thanks in advance and Happy Thanksgiving!